It's killing team diversity, it's killing mages utility ! Ofc mages can complete the game, but it's tedious, it's cheesy.
On my first playthrough, I used cheap pussy tactics to finish tough fights, with full oil and teleport assassination. Cheese is not tactic, cheese is a cheap way to win.
In the end, to play without cheesing too much --> physical team with 1 mage support. To play though the game like a breeze --> 2 lone wolves.