This looks very versatile, and that's something I like. I'd skip the MLas, though, and replace the SSRMs with double SRM4s. Better cooling efficiency and a bigger when close up. Bei aware that XL engines are pretty dangerous on the KGCs.
I haven't messed around much with the King Crab yet. This is just a first doodling. You're right though, I checked the KGC hitboxes and XL looks like a bad move, unless you can reliably maintain a stand-off distance from your target.
