Board Game Arena

It seems that if you play symmetric starting empires, there is only the choice to start with the starting empire - 2gray 1green 1black. I want to play symmetric starting empires but with the choice for us to start with a choice of another empire that we both play. This is not currently possible.

Right. That's in accordance with the physical game and its rules. The game provides a consistent symmetric empire for all players, but only one of each of the others. In addition to being a component limitation, it's also a balancing issue, which is why the rules support it this way.