Yes, I have also discovered many creatures with a help of Heroes III, but my mod won't have such reach and appeal like original game (although I hope it will be popular), so it won't introduce new creatures to minds of players the same way 3DO did or Ubi is doing now. You guys may be ambitious to find out about new creatures background, but most of people ale too lazy to do so, and I don't want them to be confused.
Besides we already have Ugallu, which name is quite exotic and Lamassu, which may not be that popular as you stated. Two "new" creatures are enough.
Anyway this is just my opinion, line up is settled anyway