Legionnaire doesn't have a model clone MkII, so it wouldn't be removed anyway.
(Although I am in favour of deleting the Decurion and buffing the Legionnaire to MkII levels as well. Not my call though.)
Why delete? The Decurion has a pretty good model, just give the 'sairs the Legionnaire back, since most seem to prefer it, but turn the Decurion into a civilian Light Fighter "inspired by Corsair designs".
I doesn't look all that much like a Corsair ship anyway.