Does it makes sense that the defending fleet of a system is forced into combat when any of the planets is attacked?
It would be logical for the defending fleet to be able to "chose" its engagements and letting low-priority planets be captures staying back for the one important planet in the system.
Else, if the defender has two planets in the system: ( one high-prio industrial powerhouse with planetary defenses and star bases and a low prio moon with no buildings and 1 pop), the attacker can attack the low prio planet with no defenses and for the defending fleet from
1. retreating from the whole system leaving the high-prio planet undefended + taking losses
2. Taking losses defending the low-prio planet without defenses of its own
Though it would make sense that the defending fleet has a "ignore invasion" option, I am not sure it would make sense game-wise:
The AI seems to already use the above mechanic and invading my low-prio planets which is absolutely fine if this is an intended mechanic, but if not, "ignore" would be a logical choice but AI would need to be adjusted to this consideration
Edit: Seems that auto retreat places the fleet back to the same star system... So this is kind the "ignore" option then?
Also: Can evacuate planet during invasion which is cool if there is a defending fleet to cover their escape but shouldn't they be caught by the attacker?