@tinavy
It's a trope that's overused across most manga, and although your arguments are valid, there are some flaws too. Team-based evalution should came at the end, not at the beginning of an evaluation.
Let's assume all tests consist of performance of a party, in that case there could be a setup where there are 2 freeloaders which could get carried by a powerful third mage through the entirety of the examination, which defeats the point of giving everyone a certificate at the end.
TL;DR First individual skill should be assessed, mages who are unfit for the rank would get weeded out, and then a team-based evaluation would be much more appealing (personally).