My first 4E character was a Warlord and I enjoyed it for the mechanics. But the problem, narratively, was that the "combat squad commander" concept, and all the abilities that come with it, were now limited to a specific class (that also had a very unpopular name, and some narratives where controversial because people defined HP/meat differently). I felt that ANY class could and perhaps should have those leader options. For instance, I think that Fighter Bannerets, Paladin Commanders, Barbarian Thanes, Ranger Lords, and Mastermind Rogues are all valid squad leader concepts that deserve to opt in to such abilities.
I don't want just one "Warlord" class anymore. I liked the things it had, but the concept didn't deserve exclusive access to those things.
I was a fan of breaking up the Warlord into component parts that multiple classes could choose from, like with a more broad Combat Maneuver subsystem and Feats. We got some of them in 5E, but I wanted them to be more broadly available.
My second preference would be to have Commander-themed subclasses for each class that allow you to pick and choose some Leader abilities from a list of options.