You never played the HOMM IV Gauldoth Half-Dead campaign did you?

Only played M&M VI, and don't remember too much of that story. But it really didn't seem like something that would have too much relation to a larger saga, considering it started with some misbehaving monsters / cults and ended in a space ship.

Well I have heard that HoMM IV has an actual decent story, but haven't gotten around to playing it yet.

Nah, actually I think they've learned their lesson and have finally figured out that DRM is bad (and more importantly, doesn't work), so they come up with a new concept, something like PRM, Physical Rights Management. You'll have to wait for a Ubisoft employee to come to your house and watch you play to play it (naturally the game deactivates and fries your hard drive when he leaves or turns his/her head away). Of course, they won't pay the employees to do these visits, because that would be bad business. Then they'll inform us of the success of PRM, a single customer bought the game, while millions pirated it after managing to crack it on the day of release. It is easily concluded that without the PRM, not even that one customer would have bought it and so the war against piracy was won. Even real pillaging pirates are impressed and shaken.

Maybe they will also conclude that turn based combat is boring, and actually the whole "playing it" part too, so you get these bars, and if you fill them by standing around or something, you can "paint" enemies and push a button after which the hero automatically uses elaborate magics / animations and instakills everyone. Resources should be infinite and towns already built. The story should be about how a girl was stuffed in a fridge, or shot or something, and the main character man is then reeaaally pissed off because of that and decides to take revenge. Every now and then, the main character hears some old man's voice giving him advice or something through magic channels. At some point the old guy betrays him and turns out to be a brain in a jar, because no one expects that. And the game is all about orcs, like any and every M&M game should be.

...I hope not.

I'm going to guess that's how you intended for it to look. Anyhow, Might and Magic isn't so much of a large saga as it is several small glimpses at the universe the games take place in. It's telling the story of the world(s), not the characters.

EDIT: Okay you edited your message since I quoted it an it is more coherent now, but my previous statement still applies, it is more of a story abut the universe than about the characters.