I think most of the challenge comes the game trying to wear out the player with damage sponge enemies rather because of attack patterns. I guess there is nothing inherently wrong with that, but I hope the series moves past that system after the Lords series is done because it can be rather tedious. I also suspect it's done in order to pad out the game.
Honestly, I've been thinking lately Castlevania should maybe drop down combo based combat entirely and only have an attack or block function or something like that. I feel 3D Castlevania games should focus less on combat and more on environmental hazards. Not that combat shouldn't been challenging, but there are other ways to do that besides giving the enemies gazillion hit points.
Regarding playing Lords of Shadow on Paladin mode, I noticed it's actually very easy. I used these three steps to finish every level without much trouble:
1.) When in the Land of the Lycans, use fairies to stun the more annoying enemies. Mash the attack button to win. Likewise, in the Land of the Vampires, it's the same thing, except you use Holy Water.
2.) When in trouble and out of Fairies/Holy Water, use the Dark Crystal.
3.) When in trouble and out of Dark Crystals, use Ultimate Light magic.
Personally, I think it's just a matter of knowing when to do what technique in order to immediately turn the fight in your favor.