In most cases, that isn't going to result in saving throws being much better than the Monk's proficiency in all saves, if at all.
Charisma save is about the only save the Paladin totally rocks at, and of course we know how (not) often those come up. WIS save is likely to be about that of a Cleric or Monk, since Paladins tend to have average WIS, making CHA simply make up for that. Other than that, Resilient (CON) typically gives the Paladin the best save there, but that uses up a feat, so there's a tradeoff. And a typical Paladin isn't going to get CON above 16, if even that high.
Hardly overpowered. Perfectly fine.