No, I don't think it's pointless at all. Characters like combot let you get to know better how really good you are with each character. It's fun to which character it is "mimicking", and well, do what you got to do with it. Besides, teh fighting style changes with each match. If you select random you'll get the same char for all the battles
P.S. I love Combot's Epilogue. It's hilarious!!!!