the max kick pull of 1.5ton could easily go upto 9-11amp max each...in that case 16A will gave up
always install separate breakers for each unit....reason breaker will be useless when both units are operating at low amps or one is closed...
1ton inverter can easily go on with 6amp breaker ....purpose of breaker is to trip and protect.. in this case it wont...it work as on/off button only
i would advice to get high voltage protector cutt off to serve purpose....