Snipe,
The craws in you pond look like Northern (virile) Crayfish. Unlike our southern craws, they have a distinct yearly cycle where they exude eggs in spring and mate and in fall. You are making good ground on the big ones but they grow fast as long as they are not overpopulated. A good time to harvest again after thinning now will be this Fall.
The virile crayfish has large claws and stand up to fish better than other craws by displaying the outsized claws. One thing that may help to feed the fish is to remove claws and throw them back. If a fish can swallow them ... they will be gonners without their claws.
The sexes can be distinguished from each other and you probably wouldn't want to take it this far but a fall harvest of all trapped males and 2/3 of the females could produce a bumper crop of crays next spring that your fish could eat.
