We have three seekers and two slots! Draco didn't get a chance to play last time, and I reckon Regulus would do better as a chaser than Harry. I played against him at school and he's got a more tactical play about him.
Theo played beater last time and did fine. I thought if we pit him against Fenrir then you won't have quite as much of a one sided match.
But by all means switch then, heartbreaker. No skin off my nose.