GCIII is a min-maxxer's paradise.   This is both frustrating and easily gameable.     The game becomes more about gaming the game than actually ruling an empire.

Examples are easy to spot and everyone basically posts on aspects of this.  From having escort ships that have nothing but defense with a fleet of ships with nothing but weapons.. to planets that focus on only manufacturing, or only research.

There NEEDS to be some sort of balance of diminishing returns implemented system wide game wide.

A planet that has nothing but production should be a hell hole of pollution so much so that everyone dies.  Upkeep for this sort of industrial megaloading should be insane...    The same goes for planets with nothing but research...     while I have no issue with having mega focus on planets  these planets should rightfully and mechanically be so expensive to the player that they are the "few gems" of their empire, not the status quo for how every planet should be.

In combat...  ships with support designation should have very limited attack and defense and should rightly be targeted last.   However if I go in with a ship that has zero defense and huge guns... the game should see that ship as the greatest threat and target it first  no matter if it is designated an escort or a capitol, or an assault ship..