A lot of people will tell you Scholar is preventative healing, but that is only partially true... a WHM can do the same thing almost as well with Stoneskin as our Adlo, assuming it doesn't crit. We don't prevent massive numbers unless we crit, mostly it's making sure you keep using Succor either before something is going to hit everyone, or just keeping it up just in case people take damage.
I mainly play SCH and was doing TERRIBLE as a WHM, burning through MP because I was trying to play how I play SCH. On a Scholar, sometimes I literally just spam Physick and manually press Embrace. You don't always need to Adlo, and you can spam Physick almost non stop and never really worry about MP. I find I do this a lot more in really high spike damage fights like Ifrit Ex, where you can't quite predict him putting the debuff on the tank along with the massive damage, in the way you can with Mountain Buster and Adlo+SS the tank beforehand. If you spam Physick during Ifrit, you'll almost guaranteed get a heal off right as soon as he takes a big hit, leaving no risk if in the same situation you would wait until he took the hit and then started casting. I've tried that, and sometimes he just keeps spamming his fire breath and because you weren't preemptively curing, it's easy for a tank to die.
And that is the main difference I see in comparing SCH to WHM. Yea you will do a lot more preventative work as SCH, but that's all fairly easy. Toss out Virus either right before a big hit or large party damage like Tummults or just use it on cooldown. Use Eye for an Eye during large pulls. Use Sacred Soil basically always if you have the Aetherflow to spare. Use Fey Covenant right before usually a primal's signature attack, Levi's big wave, Ifrit's hellfire, (not sure if Titan jumping counts), and Garuda for Reckoning. That's all easy and basically second nature. The real difference in play style is I find I cure a LOT more constantly as a SCH than a WHM, sometimes regardless of whether you need to be tossing out those heals. Hell, you can do it just cause you can and don't have to worry about your MP. Every Physick+Embrace is essentially a WHM spamming Cure 2