Bets.

Look at the humans in all the parts, except for the griffin and the angel, all are humans (well, okay, there was also the ballista in the 4th part, when the griffin was removed). The origin of the race doesn't matter; the main thing is that it's truly unique (although they've mixed humans with almost everything). As for

It's simply impossible to come up with something that doesn't exist in Warhammer.

There are several such things in the Heroes series. Yes, not much was invented from scratch there; they mostly took what was already available, but Warhammer doesn't have it. To be honest, I'm more familiar with the older parts because I'm not as familiar with the 5th one. But remember the snow elves of Wori (by the way, a unique mythical race, as are the ice giants of Wori), to which Jelu was half-related, take the giants and titans, the monsters, the thunderbirds (not Rukh, but specifically, thunderbirds are unique in Heroes), I don't remember the Gog and Magog. And I could continue the list if I went through all the Heroes and Might and Magic 6-8. I also understood about the name right away. And Forge from the 3rd game, yes. It was supposed to be instead of Conflux originally. In fact, the picture of the city is from the preview. And here's a quote from Lurkmore:

The developers initially wanted to include the Forge faction, a castle of various bio-technological creatures (like naga tanks, goblins with guns, and zombies with chainsaws instead of hands, and other wonders). This was related to the endings of Might & Magic 7. They planned to make the evil ending canonical, in which a part of the ship was used to launch the Celestial Forge, producing pew-pew rayguns and other things to establish world domination. But then they chose the good ending, in which that same part launches the Stargates. When Forge was announced and the concepts were demonstrated, the righteous Heroes fans on the entire planet united in a common impulse and threw mud at the idea on all possible forums and declared it heresy. The developers quickly put together the Conflux, without worrying about balance or anything else. That's the story.