The short answer is NO you can't. The long answer is YES you can but it takes power understanding & management. The fan of the A/C needs very little power. It is the compressor, especially at startup, that needs the power.
Running one or the other, but not both on cool, is a plan. Running only one on cool & the other on fan only is a plan. For extra security turn the waterheater off & only use it on propane if using the A/C combos. Also reduce the A/Cs to fan only while using the microwave.
50amp units need 50amp service so that all that stuff can run at once. 30amp service simply cannot provide for full load demand.
The DW is going to turn the microwave on without thinking anyway. /this could result in a trip out to the post to reset the breaker. Head her off by turning the microwave off at the circuit breaker.