If Exalted Cleave and Avenging Cleave are intended to save feats for Paladins in general, there's still more that needs to be done with them.
For Legendary Dreadnought Paladins: Exalted Cleave needs to satisfy the prereq of Momentum Swing. Both enhancements also need to have a chance of resetting Momentum Swing's cooldown, just as the feats do (don't know if this part works already).
For Paladins with Great Cleave and a non-KotC tier 5 enhancement: either a) Avenging Cleave needs to be tier 4, or b) Exalted Cleave needs to satisfy the prereq for Great Cleave. The first option would imo be the much better solution, and likely also much easier to implement, considering how the enhancement reset and/or feat prereq mechanisms would have to be altered to allow for a feat depending on an enhancement. As is, a Paladin who wants both cleaves and also Sacred Defender tier 5 (or anything tier 5 other than KotC) saves no feats at all with this, and I imagine that description matches quite a lot of Paladins.