I'm not sure on Zaha. He's strong and quick, and has good feet. The reason he gets bossed by "worse" full backs is that he beats them, then comes back and tries to beat them again and again rather than playing it quickly. If he can learn to get past them once and play it, he could be a decent player.
I watched their playoff campaign and CP look very poor without him from what I can see. He looks very unsupported when he beats a man and looks for an outlet which hopefully won't be an issue next year.