mellored
Legend
the +2 ac, advantage on dex save, and the double speed which haste also provides.Using Haste as your base model is a bit deceptive. Haste requires Concentration, but there is no real non-magical parallel to Concentration. And if there was, what else would a Warlord require in order to make it an actual trade-off?
Possibly shorter range as well. It would make sense for the warlord to be near the person he was helping / hindering.