Just putting this into perspective a bit:
Naked Hume pld/war capped healing magic:
Mnd: 85
Vit: 91
Skill: 373
Cure III: 287
Cure IV: 534
Naked Hume pld/war capped healing magic & merits:
Mnd: 85
Vit: 91
Skill: 389
Cure III: 290 (3 more hp cured)
Cure IV: 541 (5 more hp cured)
I would go with enhancing.
Good point, wasn't aware that it'd have such a little effect (have yet to mess about with the new Cure formula).
Also, by my math, a 16 Enhancing Magic Skill increase would still keep a capped D-Skill Phalanx at 29 Damage mitigated. Unless I calculated incorrectly, Paladin needs 358 Enhancing in order to achieve the 30/Hit Phalanx threshold. So that would be 24 Skill in Gear without Merits, or 8 Skill with Merits (Gallant Breeches +1, Colossus'/Enhancing Torque, Merciful Cape, Olympus Sash, Augmenting Earring, and Aptus Earring are the only pieces that come to mind). However, even with all that Enhancing Gear/Merits, you'd still be stuck at the 30/Hit threshold.
So really, just feels like a toss up between Enhancing Merits/Enhancing Gear or solely Enhancing Gear, depending on how congested your Inventory is; thankfully, none of the aforementioned are terribly difficult to obtain, so opting not allocate Merits into Enhancing is certainly viable.
Furthermore, while minimal, an extra 3/5 H.P. recovered on Cure III or Cure IV will amount to
something over time.