The general consensus is they all can do it, but that in theory (in theory) PLD = better raidwide def, WAR = more deeps, DRK = needs some love.

But a player who's good is the #1 important factor. People who care enough about meta to enforce it, instead of just theorize over it, are either speed runners or sucky players who need to rely on meta to overcome their own party's lack of skill.