I know for a fact that 118, the Robonauts, used a single bumper configuration exactly like what you are talking about. It looked like it worked extremely well, and they were able to change colors in less than a minute, which is impressive in my perspective.
I understand that you cannot have a bumper segment longer than the widest dimension of your robot, but I believe each of the segments were separated except for the corner brackets.
Check it out here:
http://www.chiefdelphi.com/media/photos/34959
And here:
http://www.thebluealliance.net/tbatv...s/2010/118.jpg