I have a very large group of people that I play with on a daily basis depending on what time is it. Some get on after work and get off early. Some get on late after everyone else has gone to bed but that leaves the people in the middle stuck playing by themselves. There is no reason the fireteam size couldnt be increased to at least 4. I have complete faith in Bungie that they could come up with some way to allow this. Something as simple as increasing the numbers of enemies and increasing their health would be good enough in my opinion. If anyone has any insight as to why the teams are limited to 3 when this is suppose to be an MMO then please feel free to jump in.