Yeah, M+M VI was a sequel to HOMM 2 and sets up some stuff that pays off in HOMM 3; M+M VII likewise follows on from the events of HOMM 3, and sets up one of the HOMM 3 expansions. For a plot-light series, it’s pretty well done!
M+M X is set in a different world - the Heroes franchise got reboot somewhere after I lost track of it, and it follows along with those changes - and it’s also got tile based movement and is strictly turn-based, so in some ways it feels like a throwback to the earlier games. If you liked VI, though, VII is much of a muchness albeit with some upgrades. And VIII uses the same engine too, which definitely starts to feel a bit long in the tooth but the “play as monsters” gimmick is actually pretty fun.
When I did some replays recently, though, I and II actually wound up being my favorites. It’s hard to go too far wrong!