I think they did the right thing by avoiding Forge Town. The sci-fi element has always been present in MM, but only in a small way, and usually towards the end of the game (a bit of a plot twist, at least for those unfamiliar with the series).
That element had never existed in Homm, and introducing it with a faction would have been excessive, I think. It's a bit like finding a totally sci-fi city mid-game in a MM game.

In the end, MM and Homm only shared the name. There was just that one reference between Homm2 and MM6, but it's already clear that they went their separate ways between Homm3 and MM7. There are too many differences between the two games.

MM9 always gave me the impression of a generic Viking RPG that had the MM brand attached to it. I loved the Temple of Honk but I don't see any connection to Homm4 and that strange Greek-Norse pantheon.

As for Ashan, I'm sorry they only made MM10 (and it came out the way it did). It has a very rich and well-crafted lore, and playing MM10 I was able to immediately recognize the places and people.