The Honda EU3000i Handi will usually handle ONE standard 13,500 BTU rooftop A/C system just fine. Some older systems maybe not, and under extreme conditions (high elevations, above 95 degrees, etc.) maybe not. Ideally, try and test your rig with a demo unit at a Honda dealer to be sure.
The Handi will NOT run two A/C systems at the same time. No 3,000 watt generator can do this...the loads are too large, especially if you fire them up at the same time.
- - -
Caveat: I work for Honda, but the preceding was my opinion alone.