Well I can weigh in on the choice of two, having watched about 5 hours of the stream. I would prefer two because it will make things more fast paced, and also, even though invasion has a lot of vehicles, it still should be based on infantry. I feel like a warthog and wraith and scorpion would be dominant with larger streets. Another thing, taking out tanks/wraiths is much easier when you are closer. Just my thoughts..