In addition to my last post (I wrote it really fast, I had to go cook pasta :c)
I'm all for having larger DeathMatches. However, DeathMatch time limits should also be increased. As it is, if I'm playing with 2 other friends (a team of 3) and we're doing 1v1's in DM, we get really low on time before we finally have a victor. If there was 4 people in DM, the time limit would have to be increased.
Also, there's the issue of having a 3v1 in DM. Yes, the solo player will have a much tougher time winning - This isn't generally an issue for me and a lot of other players who are good and have good routes, etc., but for your average MCSG player, a team of 3 in DM is something that would inspire them to say "OH @#%$^& I'M SO !@#$%^&'ED GOD SAVE ME NOW" or something of the sort. DeathMatch arenas are just too small on many maps, such as SG4. (Yes, it's possible to escape, to an extent, but it's kinda difficult to do with 3 people on your tail, or even 2)
I forgot what I was going to say next (happens a lot when I write more than a paragraph :c)