Some classes, like rogues or bards, are definitely suited to take PD(K) as a second class. Such builds, despite evidently being warriors, would be limited to simple weapons. I therefore suggest that they, at least, get Weapon Proficiency (Martial) and Shield Proficiency upon their first (PD)K level. I would also say that giving them all Armor Proficiency feats, or at least the Light and Medium ones, would not hurt at all; in fact, it would suit them.The Knight is a paragon of martial discipline. Inspiring those around her and using her superior knowledge of tactics and strategy, she masters the battlefield.
Thanks for the consideration.