Yeah that's fine. The X2N will out-power the PAF Pro, but it's not really a bad thing. If you coil cut them when they're on together (either automatically or with an additional switch) you should get a good, usable cleaner sound with some output drop, but in a good way. I'm not a fan of the X2N, so without knowing what you play and what your amp is, it's hard to say whether these would be the BEST pickups for you personally, but it's totally a valid combination IMO.
BUT...Here's a thought. One pickup that I love in the neck is the Megadrive. It has one bar magnet coil, like the X2N, and one allen pole coil. It was marketed as a bridge pickup but I feel it's a little to trebly for the bridge. Plus each coil is very different from the other. The bar coil is loud and fat, while the pole coil is clean and glassy. It is higher output, though, so it should be combined with a higher output bridge pickup. In your case, the X2N is about as hot as they come. An X2N/Megadrive combo woul dbe super cool IMO. Dimarzio doesn't advertise the Megadrive, but they'll probably let you order one. Even if they don't, I know several places to find used ones.