TwoSix
Everyone's literal second-favorite poster
The new version is bordering on OP in the healing department but I'm open to revision. The Healer could pretty much do nothing but heal between Grant, Rally, and Healing kit's but it would be a losing battle.
Let's see...let's assume a 5th level Healer Warlord with 18 Int. (Mostly because I love Int focused classes and healing classes, so this is right in my wheelhouse.)
Command Points: 7
Grant Vitality - Once per short rest, grant ally 1d(HD) + 10 HPs. Stronger than the 1d8+6 of a life cleric's 1st level cure wounds, but can't scale if needed like a cleric's.
Rejuvenation - Spend 2 HD to give ally or yourself (HD+Cha)*2 hit points, or gain a Lesser Restoration effect. I can't say I'm wildly a fan of this ability, I don't really like spend HD abilities, but it's a good option for the healer. Not quite as strong as it might be for other subclasses because Healer will probably have Charisma as a tertiary stat.
Rally = 7 times per short rest, heal ally for 1d(HD)+1d4+2+Int+Cha, or just 1d4+2+Int+Cha if it isn't a bonded ally. Ok, this is really, really good. A 5th level cleric can heal for 1d4+2+Wis 9 times per long rest, with a little bit of scaling as a bonus action, and then they're out except for Preserve Life.
Healer's Kit - 1d6+10 once per ally per short rest. Pretty much the Healer feat for free. Obviously a Life Cleric can take this as well, but it gives the Warlord a bit of a boost.
It's an interesting approach. It has more raw healing than the Life Cleric, even assuming the Cleric takes the Healer feat, but it's not as flexible at deploying unnecessary healing resources as the Cleric. You can trade a Rally for a Strike or another command, but nothing as good as spiritual weapon or spirit guardians. It's not as offensively challenged as the Cleric at its baseline, though, because of extra attacks.
I'd probably pare down the healing just a tad...I think there's two major avenues to do so.
1) Drop the baseline of healing on Rally to 1d4, or 1d(HD) if the ally is a bonded ally. Let Healer/Skald still get Tac or Insp bonus on Rally, which keeps them competitive with Life Cleric. The important factor is having a bonus action heal as a baseline, the magnitude of the heal can be lowered a lot and still maintain the important functionality.
2) Skald/Healer/Diplomat might get a few too many Command Points at the beginning. I know it's supposed to balance with the fighting styles/armor/companions the other subclasses get, but it might be a bit too much initial healing. Possible change:
-Command Points are equal to 2+Command bonus as a baseline. Command bonus increases by 1 at levels 7 and 15. (Or maybe 7, 13, 17, depending on how you want to tune it.)
-Diplomat/Skald/Healer can use the Tactical/Inspiration bonus or 2+Command bonus as their Command Point baseline, whichever is higher.