Which Haven heroes do you prefer?

Hmm... no, they're not useless against Tier 3 units. They'll definitely help against Minotaurs and Riders. Sure, Furies will give them a hard time, but you'll have to put up with it, especially since there are Inquisitors to deal with the Furies.

Then, archers would be better, since Furies attack across the entire battlefield, and Inquisitors are weak at long range, but don't forget about Shadow Lords with their "Dispel" ability. As for Minotaurs and Lizards, let's clarify: only one of the aforementioned pair can be held back by the Tier 3 units, because together they form an excellent combination - 2 hits from the Minotaur + 2 bites from the Lizard. In this case, the Tier 3 units will die very quickly without inflicting serious damage, even if they are led by Laszlo. I say this with confidence because I've seen this combination break down much stronger opponents many times, sometimes you can even avoid attacking with the Lizards (so they don't retaliate) and just position them close to the target.