Which level 4 monster is the best?

I've played Heroes 3 a lot, and I haven't seen a powerful sniper stack. I don't understand what the argument is about. Vampire lords are good, although they can't always be upgraded according to the rules, and not everywhere. But they are good, of course. It's true that their strength doesn't increase linearly. But a retaliatory strike is powerful. I need to try playing as Vokial somewhere where there are no restrictions. It would probably be fun to have them defend castles.