AD&D2E: Complete Paladins Handbook

[Orius]

I'm curious: What was the rationale for recapping First Edition rules in the Paladin and Ranger handbooks?

No idea. The Paladin, Ranger, and Druid Handbooks all recapped the 1e rules from the PHB and UA. I think it was for reference for the 1e holdouts or something. There was also a brief recap in the Bard's Handbook, but it wasn't as extensive as the others.