How do you avoid losses in the game with baal? That's going to be interesting with trolls (or demons, but the executioners don't have that much HP), because Bill Gilbert alone can't beat him. If you plan on playing with only 1 troop, unless you're able to use double geyser every time Baal summons demons, it sounds kind of hard. In addition to that, baal's smashing sword skill that attacks multiple enemies is a pain and will force you to do quite a bit of resurrecting afterwards.
In any case, good luck with the attempt, if you plan on doing it
It is going to be interesting to see if anyone can be successful in getting a no-loss game.
EDIT: It may be worth trying in lower difficulties and gradually going up. It worked that way in KBTL, it should work here as well.