Soul Reaper is that beetle right? I don't really like to spam them. I rather have strategic bombers make the main assault, supported by air superiority fighters and a few Soul Reapers to pick off heavy AA strongpoints. If I'm Aeon, I have a CZAR back them up instead. If I'm UEF, then I have a mixed gunship force of T2s and T3s. That's what I do if I choose an air assault.
If I'm gonna groundpound, I'll anchor the line with experimentals, Monkeylord/Fatboy/Colossus, and have T3 assault units and flak units cover them. I'll also have 20-30 T3 fighters in the air to keep strategic bombers away; my standard fully loaded CZAR if I'm Aeon. Fatboys provide artillery and direct fire, but if I don't have them I have a handful of T3 pieces to provide support. The experimentals are mostly there to tank and distract.
Naval is easy. It's probably my preferred theatre. Use subs and hunter killers to sweep ahead, and maintain strict aerial superiority with a loaded aircraft carrier and cruisers. The main hammer are the battlecruisers, of course, and covered with destroyers.