One thing that might be noted, is that generally speaking, ComStar doesn't have access to Royal variants, their Star League era mechs came from the main line units (though there are some exceptions: Wasp, Locust, and Ostscout looking at the MUL). Not a huge deal, and easily justifiable, but depending on how strict you want your force building might be something to adjust.
Outside of that, when thinking about bringing these together into a full Level III I think you're missing just a bog standard battle formation, though your probe Level II has similar makeup. Maybe a medium battle Level II, something to be on the line while the assault force spearheads and your faster units fill in gaps.