I picked #2. I could have gone with "not interested", but I kinda am, in a very minor way. I think it would be extremely difficult to do without giving the Warlord magic, risking suspension of disbelief, or just falling flat.
That aside, I'd probably focus on ways for the Warlord to allow others to use Hit Dice during combat, boost the effectiveness of Hit Dice between combats, restore Hit Dice during short rests or gain more during long rests, etc. It might not be specifically Hit Dice, but I'd see it generally having that sort feel to it. You could even give them a pool of "Command Points" that can be used for healing(ish) and other things.
The balance to walk, though, is between the Fighter (Battle Master) and the Bard (Valor). If you let the Warlord spend the points and attack, they end up effectively a Battle Master with a few other Maneuvers. If you don't, then they're either weaker than the Fighter or you increase and fluff out the Commands. Without the attack in there, and with more potent abilities, you're left asking when they can be used and on whom. Saying "must be able to hear" or "must be able to see" the Warlord is just reskinning verbal (issue a Command) and somatic (point to where the subject should move/attack) components. At that point, just use the Bard. If the specific selection of abilities for the Bard is displeasing, the casting Warlord could be done as by changing the spell list for the Eldritch Knight.
Again, I'm not saying that I'm opposed to building a 5E Warlord. I just think that it's a pretty narrow path with minimal return other than checking a box for 4E fans.