That's true, but there are some pretty good-looking fanmade models, particularly in the SC2BW mod. (E.g. this Devourer
, this Queen
and this Arbiter
would be good enough for me). I've downloaded the assets from that mod, but I've not been able to get them into my SC2 Map Editor. I'll have another go later.
(EDIT: Yep, successfully managed to get the Queen and Arbiter. They're not as good as Blizzard's models, but they'll do. Can't get the Devourer - it's coming out looking like a Corruptor for some strange reason - but I might just abandon that, as it was going to be pretty similar to the Corruptor. I'll use the Protoss Scout or Corsair instead.)
Progress on this mod is going well: I've got 15 of the 18 ships designed, and have given most of them at least an initial playtest. Balancing the weapons and augments out between the ships is going nicely, although I've had to add duplicates of a couple of ion weapons to be able to give them appropriately Zergy/Protossy names.
The Zerg, Terran and Protoss all have a very different playstyle: the Protoss are easiest due to the shields but each ship plays differently (e.g. Void Ray's Prismatic Beam is devastating but does take a long time to charge; Carrier you can't tell to target down specific systems). Terran have a bunch of fun abilities and the SCVs+MULEs let them recover quickly from damage. Zerg are definitely hardest; the parasitic healing arm is useful but they do still tend to fall apart, but I'm trying to give each one a benefit to make up for it. Mutalisk plays very well with the Weapon Pre-Igniter and three basic lasers as the triple-impact Glaive Wurm.
The main effort remaining is the fiddly alignment of weapon mount points and determining offsets of the image vs the layout. (If only FTLShipEdit did those, this would be much easier.) Plus whatever event tweaking I choose to do, of course, but that's a different and very deep pit I'm not leaping into just yet.