there are three factors here
Engine size/capacity
Alternator size
Inverter electronics
I'm guessing the overload sense/alarm is part of the inverter controls
A monitor circuit for your the input or output of the inverter
The circuit breaker is possibly a magnetic trip, those respond faster to excess current/over the limit, than thermal breakers
And they did not have to cool down before reset
I'm pretty sure the alternator and inverter cost more than the engine
And the circuit protection is geared to them, not to the engine
