There are 142 robots attending championships who can consistently score 4 or more boulders per match.* With the tower strength at 8, that would mean that there would probably be enough pairings for all 64 playoff alliances to reliably get enough boulders for captures with just two robots, freeing up the third to do something else.
There are only 61 robots attending championships who have proven they can consistently score 5 boulders or more per match though. This means that, given the tower strength of 10, only the top ~3 alliances in each division will be able to reliably get enough boulders for captures with just two robots. The lower seeded alliances now have to think very carefully about what their last partner should do, because they will likely be unable to capture consistently without extra support. Defense also has a much higher potential to dramatically swing scores now.
*
http://www.chiefdelphi.com/media/papers/3248