For those who main/semi-main a DPS (e.g. DNC, RDM) but like Healers...

[Shurrikhan]

What exactly is this "4 Healers Model"?

I'm sure Ren will clarify better in just a moment, but an outsider's summary can sometimes be helpful, too, if only to show which parts actually convey well to different groups/people:

Rather than letting each job develop without restriction as far as seems reasonable per their core themes, the "4 Healers Model" sort of sub-divide the jobs into different categorical niches meant to appeal to a portion of the overall healer playerbase to ensure that each "camp" has a job meant for them.

Its likely problems are that it seems to assume that gameplay desires can and will be held separate from desires for particular themes, aesthetics, and so on, and that those gameplay desires must be clustered in mutually exclusive ways, so if you like both the gameplay elements that end up allotted to Job A and those that are allotted to Job B, you're screwed, and if you like the gameplay elements of Job A but the visuals of Job B, you're also kinda screwed, since you can't simply have a larger kit capable of meeting both gameplay aspects (especially, prior to extreme optimization). It can also get a bit screwy if the number of camps don't perfectly match up, some camps are considerably larger/smaller than others, etc. It also ignores where multiple gameplay desires, given the extreme amount of lenience in this game, do not have to be mutually exclusive to each other (having both X and Y doesn't mean that one actually needs to use both X and Y, even if they aren't necessarily on shared resource costs).

Consider it like if you had an uncapped way of spending Cards towards direct offense; it'd be slightly inferior, almost always, to spending them to buff an ally, but you might have that option, so if you really, really don't like tabbing through your allies to select the best recipient, you could just Lord your target and be done with it. But if you make AST specifically the "buffing job" rather than a "Cards job", or prevent it from having extra buttons that could feed into offense because "there's already a healer with more than just 4 attack buttons", then it'd be disallowed.

Honestly, the differences aren't necessarily huge; the biggest gap is in the principle between approaching things as zero-sum (someone's gotta get screwed over / there can be no increase to total satisfaction, only fairer distribution of satisfaction) or reconcilable (no positive desire has to be screwed over / there can be an increase to total satisfaction, and such should be provided insofar as is possible first).