Analysis of the Ships in the "Void"
A confusing number of different ships appeared in VOY: "The Void", when Voyager was trapped in an isolated region of space without stars and without any natural energy resources. Tuvok analyzed that 150 ships were in scanning range, only 29 of which showed lifesigns. The following is a chronological analysis of the ship appearances.
Ship 1 - "Vaadwaur"
Just after its arrival, Voyager is attacked by a hostile vessel (ship 1). This ship is analyzed by Tuvok to have a "Vaadwaur weapons signature" and to use components from several other races. It is once referred to as "Vaadwaur ship" later. Actually, since it doesn't look like the familiar Vaadwaur fighter design, the ship most likely isn't of Vaadwaur origin at all, knowing that only these fighters survived the destruction of their home planet 900 years ago. If anything, it may at most use some Vaadwaur technology. The ship design is actually a re-use of the vessels from VOY: "The Omega Directive". Since this design also appeared as Bathar's ship in VOY: "Memorial" one season earlier, the ship in the Void could be related to the latter.
Ship 2 - [Devore design]
Another vessel appears and begins firing at ship 1. When ship 1 retreats, ship 2 opens fire on Voyager, disables the aft shields and beams away food, deuterium and equipment. This vessel is not identified as belonging to a specific race in the episode. The model is the same as of the Devore warship. Since the Devore shouldn't have any business thousands of light years from their homeworld, we should pretend the ship in the Void is a completely different design.
Ship 3 - Valen's ship
Valen, whom we can identify as Annari from VOY: "Nightingale", appears and offers an alliance to Voyager - to raid other ships in a common effort. When Janeway refuses, Valen leaves. His ship is a re-use of the "Nightingale", a modification of the Federation fighter. Even if we deny the similarity to the much smaller fighter (we obviously have to), it doesn't seem to make much sense that the medical transport used by the Kraylor has become a formidable warship in the Void (unless Valen has really superior tactical officers and engineers). On the other hand, it is plausible that of all people in the Void Valen may have captured a ship of the Kraylor, who are enemies of the Annari. ALthough it makes limited sense, it is possible that whoever composed the CG designs for this episode confused the two races.
After an unsuccessful attempt to escape from the Void, Captain Janeway decides to find ship 2 that stole the supplies. Ship 2 is found burning, its crew dead. The supplies are gone. In the engine core, however, an away team discovers an unknown humanoid lifeform. The Doctor will later give him the name "Fantôme".
Tuvok and Harry find out who is responsible for the destruction of ship 2 and took away the supplies: It is Valen (ship 3). Janeway demands that Valen give back her property. When he denies, she orders his shields to be taken down and Seven beams back the supplies. There is a possible inconsistency with Valen's vessel, when we look at Seven's display during the beam-out. It doesn't show the schematic of Valen's ship 3, but of the Zahl ship from VOY: "Year of Hell". The Zahl design isn't visible once in the whole episode, at least it is not recognizable anywhere. Since the same display is shown later in the episode among the enemy ships, this first occurrence doesn't seem like Seven was just looking at a random ship schematic from the database either.
Ship 4 - Nygean
Janeway decides to follow the Federation Charter, and she has the idea to gather allies for an attempt an escape together - anyone who would refrain from theft and violence. The first contact is with a Nygean vessel, whose captain, Garon, is initially skeptical. Oddly, the Nygean vessel isn't the familiar design that had been established in VOY: "Repentance", but is a re-use of the Hazari ship from VOY: "Think Tank". It seems very unlikely that the Nygeans would use this design. One of the best opportunities to bring consistency to this episode was squandered.
Ship 5 - Hierarchy
The typical Hierarchy vessel (the shorter of the two variations) is a new arrival in the Void. It is a survey ship, not built for combat, according to its crew, and Janeway tries to protect it from two attacking vessels. The Nygeans later join this effort, thereby showing that they agree with Janeway's conditions. The crew consists of members of the Hierarchy, which makes it the first (and only) match of the episode.
Ship 6 - [Mawasi design]
The first vessel attacking the Hierarchy is Valen's ship (ship 3), the second one is a new one. It remains unknown to which person or race it is supposed to belong. Anyway, the vessel previously appeared as Mawasi ship in VOY: "Year of Hell". Clearly, we should suppose that these two designs have actually nothing in common, as Mawasi space is thousands of light-years away. It is also notable that ship 6, the Mawasi design, is called "the smaller vessel" in dialogue, compared to Valen's ship, although it doesn't look all that small.
With the Nygeans and the Hierarchy on her side, Janeway gathers seven members for the Alliance. It is possible but unlikely that one or even two of the villainous vessels, namely the Mawasi design (ship 6) or the "Omega" design (ship 1), have switched sides and are now with the Alliance. We know that one new member, namely Bosaal, will later desert to Valen's counter-alliance, which includes these two vessels. At this point, Bosaal's may be any of the new Alliance ships, none of which may be identified with certainty.
Ship 7 - ["hammerhead" design]
After Bosaal admits that he has acquired a device from another ship outside of the Alliance, a Kinjali frigate, by killing its crew, he is expelled from the Alliance. Two other members, the Jelinians and the Kraylor, leave with him. This is curious, knowing that Valen is using a Kraylor design (the "Nightingale"), but the Kraylor obviously don't (although we can't exclude that one of the barely recognizable vessels of the Alliance is another Kraylor ship). Perhaps they switched ships at some point, considering how long a time they have been spending in the Void? But then why wasn't his ship identified as Kraylor design? Anyway, with three members gone, four are left to attempt the escape from the Void: Voyager, the Nygeans, the Hierarchy and a fourth vessel (ship 7) whose name or affiliation remains unknown. But we can easily recognize it as the omnipresent "hammerhead" freighter. This design has a long history. The filming miniature was originally built for the Husnock ship and repeatedly modified such as for the Jovis or the Bajoran "Antares". Without any visible modifications, it was turned into a CGI and used in the Delta Quadrant, where it definitely doesn't belong, as a Nuu'Bari vessel in VOY: "Flesh and Blood". The ship 7 in the Void could be easily such a Nuu'Bari freighter.
While the Alliance is preparing for the final fight against Valen's fleet, several tactical displays are being analyzed. It seems odd that the schematic of the already destroyed ship 2 is among them. But this may be plausible again, as it may serve to analyze the enemy's weapons and tactics - considering that ship 2 was destroyed by Valen. Once again, the Zahl ship is on display, this time definitely not as a random depiction, but with Chakotay pointing at it. Obviously he is discussing a plan to disable the ship's drive with the help of Fantôme's people. Apparently someone who made the display must have mistaken the Zahl design for something else (perhaps for the Mawasi ship that is somewhat similar and had appeared in the same episode "Year of Hell", rather than for the "Nightingale"/Federation fighter).
Ship 8 - [Ankari design]
Valen's fleet consists of four ships after Bosaal and two more have joined - perhaps exactly the two other ships that left the Alliance together with Bosaal. On the other hand, this would mean that Janeway had admitted to the Alliance two members that were known from the beginning for their open hostility, namely the ships 1 and 6. In their order of appearance, the enemy ships may be identified as: Valen's vessel (ship 3), ship 1, a new ship 8, ship 6. The new ship 8 can be recognized as the Ankari design, which had first appeared in VOY: "Equinox" and later in VOY: "Drive" as a racing shuttle. Most likely its new incarnation in the Void is not related to the latter. But knowing how far the Ankari have traveled from their homeworld already in "Equinox", it wouldn't be surprising to encounter them in the Void. On the other hand, it is well possible that the Ankari design (ship 8) is actually Bosaal's vessel, and the two other ships 1 and 6 never belonged to Janeway's Alliance. At least, this seems most plausible.
Fantôme's people manage to shut down power on Valen's and Bosaal's vessels. Valen's fleet turns away from the opening vortex into normal space, and the four Alliance vessels (Voyager, Nygeans, Hierarchy, "hammerhead") manage to escape.
Summarizing, we may have desired to see some new and some more fitting ship designs in the episode. We probably can't find out with certainty which is Bosaal's ship. It may be any of the three other vessels of Valen's fleet.
There are also some notable oddities (or rather annoying mix-ups?). The display of the Zahl ship must be regarded as a logical error, as it definitely isn't among the enemy ships. Valen, the Annari, is using a vessel of Kraylor design, whereas the Kraylor themselves don't. Another problem along these lines is that the Nygeans are on a Hazari vessel. It may have been better for continuity to use the ships in the established fashion. Only the Hierarchy ship is correct in this respect.