Swordmages make better mass minion slayers than defenders(well, at least they have the potential, just go thunderball).
Swordmage on the other hand can only mitigate/punish once per round, but can can spend 4 feats(3 if he hybrids wizard) to make his at-will attack close burst 3. In fact a hybrid wiz/swordmage is an excellent minion wiper who can also lockdown the bigger baddies.
Yeah, Swordmages are secondarily controllers, so it makes sense they're kinda good at doing controller things. The odd part is that they're about as good controllers as defenders. I'd say a Swordmage|Wizard is a controller with a sprinkle of defender.
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