Surely you though you cant say the Titan Xp is a better overclocker based on its base clock speeds. Those numbers used are conservative and more so given its a blower style cooler. Otherwise you could say a FE 1080Ti is a better overclocker then a aftermarket 1080Ti when in reality its just the former starts off at low numbers with the blower cooler. Sure in % increase they appear to better, but in absolute frequency all top out at similar numbers it seems with some variance for silicon lottery.
The point is FE cards are better overclockers than AIB partner cards as they start with lower base clocks and this needs to be remembered when reviewing/testing. I find it all a bit silly when a review site tests a non reference 1080 Ti for example and then announces it is faster than a Titan only for the end user to find out that once you overclock both that the Titan comes out on top.