Corsairs (with both blades) deal 4,17 wounds per unit of 10, so if they are lucky (or opponent is unlucky on saves) they can kill one Throggoth. Halberdiers f.ex. gets 4,33 (due to bonus to hit at 10 models), and Endrinriggers deal on average 3,33 wounds per standard 3 model unit (and yes both of them have rend and any luck on side of Riggers with damge rolls will be devastating, but still).
And now corsairs get buff to hit starting from 15 models, not 20, have better save against shooting and buff of fleetmaster is also better. And they are pointed the same as before from what I have seen. Could be worse.