We'll have to agree in disagreeing, then. Freecure procs won't be enough to grant better MP management simply because the amoung of MP a WHM saves by getting those procs matches what an AST saves from having spells that cost less MP. For example:

Cure costs 442 at level 60; Cure II costs 884;
Benefic costs 354; Benefic II costs 796;

15% chance to proc Freecure means that one of every 6-7 cures you cast procs. You can get more and you can get less, that's RNG, but you have to be ready to face situations in which you don't get any procs, so it evens out in the chance rate. 7 Cures cost 3094 MP while 7 Benefics cost 2478. A 616 difference. That's what? 3/4 of the cost of a Benefic II? And you save more from the other spells, save more from the fact that Essential Dignity is a very powerful healing spell with a shorter cooldown than Tetragrammaton, saves from Synastry, saves from Lightspeed on intense healing situations, save from the amazing Regen effect from CU, you can also save MP by extending HoTs with Time Dilation. Assize has a long cooldown and is not that reliable as an MP regen tool, specially if you're saving the skill for specific parts of the fight. Also, I line up my LA with cards so I can use CO to buff the party.