You don't really need a great weapon against skaven, you'll cleave through them with as much as a toothpick anyway
. For that reason I also wouldn't include greatswords. Also, I'd swap one cannon for a mortar.
Eight is a bad number for Knights.
Change the swordsmen to spearmen. You don't need disciplined troops, but lots of attacks to throw at them.
Take some extra dispel scrolls.
Good luck
.