Not necessarily. I don't see a reason why person B would have to have something he's better at than A, except maybe statistical - there are millions of things a person can be good at, so the chances he's worse than the other in all things are very small.

But then still, it's entirely possible that person A is better at many more things than person B. So 'equal' as in 'A and B are the best in an equal amount of things', I don't see any reason why it would be so.