A few missed chances should erase Giroud's season long superiority over Welbeck at centre forward? Dumb, frankly.
I've yet to see any substantiation of the thesis that Giroud, relative to any other striker, only functions effectively in his role when we play a high line and dominate possession. It's a made up fact. Welbeck has lots of pace, Giroud doesn't, but if that really makes us a killing machine on the counter we're certainly yet to have that theory vindicated.
There is a sound reason to argue in favour of dropping Mertesacker and against dropping Giroud. One's been out of form and the other hasn't.