My industries are farming and mining, no heavy industries and I have a patrol station and an orbital station, I am using one gamma core and it's on my patrol station iirc. I feel like none of that is too crazy to warrant such a massive fleet.
You're right, that doesn't
sound like to much, and sorry for making assumptions. With that said, let's look at some
possible issues.
Mining attracts expeditions.
AI Cores attract expeditions.
You don't have/don't know money can bribe them.
You don't have/don't know reputation can bribe them.
Your orbital probably isn't strong enough. (Tier < 3)
Your patrols probably aren't strong enough. (Tier 1)
Your fleet is to small / ill-equipped.
Your fleet doesn't have enough officers / has poor officers / has aggressive officers.
Your colony has poor stability (Stability affects patrol ship strength)
All or part of this can make starting a colony early a real pain. Keep in mind, you don't
have to start any industries, and given a decent world, just the basic structures can produce a profit.