Trying to bomb strats in a ftr is a complete waste of time unless there are several of the ack towers down, poof before you can even say it.
Knights are often defending their strats from nearby bases, when has this happened to Rooks lately?
Oh, I wouldnt say that it is a waste of time taking a heavy fighter to the strats. 1 single P51D can do a lot of damage in one pass. Same goes for the P47D-40. We'll make a single pass through the auto ack and drop everything on 1 factory and then RTB.
All three chess pieces get their turn at getting their strats hit hard, I'm not seeing any one side get any more than the other, really. Actually, I can't remember the last time I hit the Knight strats. However, almost daily I'll hammer the squeakops at least once.