I think EA or somone said that the reason why the Angarans and Kett are the only alien sentiant race in in the game was cosplay related. But this was years ago, and I think there were other reasons.
But I was confused what desigbs did they say "Wait, we can't have those races in the game. How can people cosplay?!"
The Asari are easy, the Turians might be more difficult since the physical size is not drastic, but the armor should as some room for the cosplayer, and the Krogan has plent of room. The Quarian cosplayers basically just need to cut 2 of there fingers per hand, and have some hips that don't lie. Salarians do have the least physical accommodating body shape for most people.