Thats an interesting way to look at it, definitely possible. Or a sole survivor area. PLUS, if we want, we can go Terminus Systems style, since it hasn't been developed at all, except for Omega in the 2nd book, we could easily fictionalize a lot of stuff. It also gives good credit to why a quarian, Alliance Military(Or just Human) and asari commando would come across each other.
ALSO! Yes I love Garrus, especially later in the game if your Paragon. He changes for the better, but I really hope he is in the 2nd game, at least a little bit, just to see how things are going if necessary. But hes cool, I really like him for Insanity difficulty, cause his tech and combat mix make him great for fighting geth, specially mixed with Liara's biotics which can disable or instantly kill harder enemies with shields and Immunity, plus Garrus can disable weapons and shields, but also has some combat efficency.