A good testing team would look for loopholes to things, try to break geometry in game, try to find any possible bugs in countless crazy ways, try to dupe, try to do anything a crazy good player would try with a database with classifications of various bugs
What Blizz team does I have no idea.
Someone on these forums tried to tell me the in-house testing team has accrediations from a college or some BS and I about laughed my bumbum off IRL.
No good gamer ever needs accreditation to break a game in any way possible.
Damn I miss Levelord.
We the players should not be the testing team