Probably depends on how left-footed they are. Has Laporte ever played on the right of two central defenders? I can't remember him doing so. I think he'd struggle there but I can see him being OK in the centre of a 3. Ake? Perhaps he can because if he can play defensive midfield - he must be pretty comfortable with both feet?
Much of this speculation stems from not seeing City in pre-season and the natural desire to see City overkill the key weakness in the squad.
I always assumed that Ake would cover Laporte, allow City to play 3 at the back if we wanted to, or play as a deep midfielder which is also a weakness for City.
Useful graphics follow from Totalfootballanalysis but we need to consider that he was playing for Bournemouth a side that would be under a lot more defensive pressure than City.
(They also have a very specific article on how could Ake fit into City:
Total Football Analysis)
If you look at the graphics you see that Laporte is a playmaker. His pure defensive attributes don't appear that good but then some defensive arts such as closing down without diving in, and shepherding a forward away into a safe area aren't captured.