I've seen teams of 12-14 do very well. If you're at a gym with only 8-10 level 3 tumblers who can stunt their buns off, you could easily put together a Senior 3 team of 12-14 with those numbers and do well on any scoring grid that takes quantity and majority skill into consideration.
Anyone who is old like me would probably remember Kennesaw State U's "dirty dozen".... 12 girls with full team tumbling who came in 2nd at NCA college nationals in 2002 against teams of 20. If anyone has a video, put it on youtube, because all I have is the vhs lol :)