In the last week, I tried to route the Price of Loyalty campaign. It was fine until the last two scenarios. Put it this way: the Roland campaign takes about ~200 days; this took me 309, and half of that was for those two. Between the necessary scenarios and difficulty spike towards the end, I'm thinking this might be a 3-4+ hour speedrun.

You can skip playing 3 out of the 8 scenarios, but you will be severely handicapped for endgame. Having the artifacts and free Elves make for a consistent route and should save more time than building troops.

As for difficulty, most maps are rush the AI and are fairly straightforward. Except the last two. I would say #7 is worse than #8. #7 requires the AI doesn't open all the gates (terrible map design), then either building troops or getting Dimension Door. #8 is easier with the use of Town Portal, but goes to hell if Red gets Dimension Door. Most likely they do as they have 5 castles. And about 1000 of each undead troop. Joy.

I might stream this sometime by the end of next week, as it'll be Spring Break for me soon.