They are trash. The people who like them are also trash, largely because the idea of a mechanically-imposed "Leader" is awful, and also because they generally just exploit action economy which is why they were so powerful. They're for little people with big egos, the napoleons of the table.

They don't fit in a skirmish scale game, especially one where each player is encouraged to make their own decisions and not be lead by an appointed "tactician."

If a class is going to grant extra actions to other characters, it should be done not because they're so brilliant at shouting orders, but in a more humble and perhaps even humiliating fashion where the player is forced to acknowledge their character's own actions are mediocre in comparison to the people they depend upon, and that they are less the mechanically-appointed de-facto leader and more of a glorified cheerleader.

Rather than a "Warlord", I'd prefer Fire Emblems take on a class that grants extra actions.