Sounds like a great idea. I have finished HOMM VI main campaign along with the Pirate one and now doing Dance Macabre. Still have a ways to go. I waited on HOMM VI until all the patches were out so waiting on MM X will not be too hard.
I hope MM X is up to standard of the rest. I started at MM VI and went through MM IX including the mods. I can't recall how many times I have played each. I have gone through the HOMM I - V and now on VI. BTW, I thought HOMM IV was Great. It had a better RPG feel to it. I had a 7 heroes army only and pretty much wiped the maps with them (customized them). I tried MM I thru MM IV (after MM VI), but could not get into them. I did all of the Bard's Tales so they had a somewhat similar feel.