I suppose I'll give a shot at making the old A-game Paladin as an Oath. 5e's Bardic Inspiration is a significantly better tactical tool than the 3.5 version of being just a buff.

...Burning spell slots on Bardic Inspiration seems pretty underpowered, unless it's swapping the Smite dice for Inspiration dice directly, in which case it's overpowered without some harsh restrictions. Maybe have it be a swap with a restriction of Inspiration dice per die roll, with the 7th or 15th level features including an extra simultaneous die. Drop it on an archer then charge in, trusting the archer to wisely use their allotment of Inspiration dice, is pretty tactical, right? A d6 bends bounded accuracy(nearly removing the "super-expert high-level badass fails DC 20 check" situation 5e seems to love), but doesn't overpower the d20 enough to break bounded accuracy(nublet will still have only minor chance to hit fully-grown dragon).

Okay, 3rd level, Channel Divinity for a "free" Inspiration and a heal modelled after a mix of 3.5 Lay on Hands and 5e Song of Rest, with 7th level carrying the Smite to Song effect of Inspiration dice replacing Smite dice that are usable one-at-a-time, replacing the usual Aura effect at that level, then 15th level gives Charisma modifier uses of Channel Divinity per Long Rest and two Inspiration dice uses at once, while 20th level carries a continuous Heroism aura(so Fear immunity and Charisma mod temp HP every round in 30 ft.). 18th level shifts the Inspiration dice from a 10 ft. single-target limit, able to target self, to 30 ft. range distributed, allowing for handing out up to 5d8 split among the party as desired that's usable 2d8 at a time. Not sure if I want to have Improved Divine Smite be giving an automatic d8 of Inspiration each round or not...

For Oath Spells, Heroism is an utterly obvious one(what's it's actual duration? d20SRD lists Instantaneous for some absurd reason). Healing Word isn't on the default Paladin spell list, according to the SRD, and works quite well on a support-oriented Paladin by avoiding action conflicts between healing and attacking/buffing. Prayer of Healing is excellent non-combat healing, and Enhance Ability has lovely options to it, so those two get to be the 2nd level slot. Beacon of Hope is a crazy synergy with Prayer of Healing, and eats Concentration better spent on buffs, so the 3rd level heal side is Mass Healing Word, for when the whole party has scratches to deal with, and the 3rd level buff can be Protection from Energy, so that scratches are more likely. For 4th level, Death Ward can be the "healing" side, covering an ally liable to get killed so you have healing response time, and the buff can be Stoneskin. 5th level healing is Mass Cure Wounds, basically longer-range, less-potent, in-combat Prayer of Healing(or multitarget Cure Wounds...) so that healing the whole party mid fight for a decent amount is on the table. Then Dispel Evil and Good(the Good and Evil spell thing needs to die, now, because 5e is finally giving Undead and Fey proper Outsider attention...) can cover the buff.

Hallow makes for a good "frill", but is actually kinda crazy in some situations because no-save permanent generalized Outsider denial. Fiends, Fey, Celestials(they can possess things now?), Undead and Elementals are just flat out not able to enter, without any save to get around it. It... completely kills any sort of high-level siege narrative involving most of a creature type and all of three creature types if it does get used.

Now, Oaths... The A-game Paladin was, thematically, all about being support, as far as a Paladin can substitution level, AFC and feat into. It led the charge, yes, but did so by making everyone else better able to handle the charge with them. So Oath of Courage seems an appropriate name. Any ideas for Tenants? Because I've got literally all the mechanics mapped out to type out in the next two hours or so(got a PRC to finish up with confusing wording to manage)