I would much rather consolidate, but agree that it's super annoying. I've had the Centurion since it was issued in Canada, more recently in the US, but I'm pretty sure the reward benefits in Canada were initially better than the other cards - doesn't make sense to me that the entry level cards would have better points benefits.
But I'm trying to use up points with Chase, Citi, RBC and others so rather than keep spreading them around I decided to try getting a few extra AXs and see if it's easier to consolidate them in one place. The rep was basically recommending it, which is also a bit odd. I will continue to reinforce your comments though, i completely agree.