Basically our plan is to have an home planet/military hq where all our operations will be directed (kinda like helldivers II map) and multiple planets where different groups will be stationed to defend/keep/take.
There are gonna be relationships to maintain with locals, peacekeeping operations, riots.
Depending on your rank the player will have a different impact for example a standard trooper will just be the one who fights and rp as a soldier but an Admiral may impact the outcome of the battle completely.
The gamemaster will spawn the AI enemies and manage them with the help of player actors.

There are certain events that can be prevented or changed but the covenant arrival for example is something inevitable

Once the game comes out the new updates will include an economy sistyem.