Well, remember that a job is an optional specialization, and that they're meant to de-emphasize cross-class skills in general. Also, because they're specializations, they are meant to be more self-contained than classes, and less reliant on cross-class skills in general.
So take Pld.
Pld can slot Cure (Obvious effect), Protect (Obvious effect), Raise (Obvious effect), and Stoneskin (10% damage reduction) from Conjurer. Then from Marauder, it can slot Foresight (+20% Defense), Skull Sunder (+enmity attack), Fracture (+enmity and DoT), Bloodbath (25% of damage dealt to health, 15s, 90s cd), Mercy Stroke (High Potency Attack).
Realistically, you won't need Conjurer above 34 or Marauder above level 26 to get full effectiveness of the Pld. And you have everything you need from Conj at level 12, so you're already over-leveling it to unlock Paladin.
You have 5 abilities. The sad reality of the Pld in this game is that you probably won't want to take Cure. Interrupted spells don't give you enmity, and low-healing spells don't give much either. You're not really the AoE tank, anyway.
You're probably going to slot Foresight, Fracture or Skull Sunder, Blood Bath, and Mercy Stroke. Then you'll either take the other offensive Marauder ability (of Skull Sunder or Blood Bath) or maybe Raise/Cure.
You don't need to bring Protect or Stoneskin, as your Sch or Whm will have them. You don't really need Cure, because it's fairly low threat, with a high chance to be interrupted, and negligible healing.
Raise is nice, in case your healer bites it and everyone else is in a Job and, therefore, cannot slot it.
But otherwise, at least 4 of those slots are going to Marauder abilities. +20% Defense is a no-brainer. Blood Bath, too. 15 seconds to self heal for 25% of your damage? Nice, particularly if that healing supplies enmity. Mercy Stroke, Fracture, and Skull Sunder will come down to TC.
Skull Sunder is 60 TP for a 100 Potency attack with increased enmity.
Fracture is 70 TP for a 100 Potency attack with increased enmity that inflicts a 20 potency, 18 second DoT.
Mercy Stroke is a 200 Potency attack with no TP cost, a 90 second CD, and can only be used if the target is under 20% health. But if it kills the target, you get 20% life back.
So, assuming you want Mercy Stroke, you need Marauder at 26 and Conj at 15. If you don't want Mercy Stroke, you only need Marauder at 8.
8 and 12 aren't really much to ask, to have access to all but 2 of your possible abilities.
It'll be close, but Romney has the momentum.