Norman knights (stat-wise) appear to be comparable to Chivalric Knights. On the whole, a Norman knight has more attack while the Chiv has more defence. In battle, they appeared to be a match. But then again, I haven't fought many Chivs in my campaign so far.

Norman Knights are cool, until they get their armour upgrade. They look like any other late-era knight then, which is a shame. I loved that visor.