I don't think it's baffling at all. In fact, I think it makes total sense that a support class falls behind the main warrior class. Because they are a support class, not a baseline warrior. And have other features focusing on support rather than martial DPR.
But they are a warrior. They’re not a front line damage dealer, but they’re still a warrior. They’re like the ranger, except hopefully designed well. If you don’t take damage spells, and find a support/exploration focused subclass, you aren’t going to be in the top half of damage in the party, but you can still fight competently when called upon.
The warlord just gets support features instead of exploration features, and more support abilities than non support abilities.
Using extra attack with options to replace attacks with support manuevers allows the class to choose at each attack whether to focus on support, or to lead the attack.
And leading the attack should not be a secondary archetype siloed into a subclass. It should be one of the primary ways to build nearly any member of the class.
whether it’s a vanguard, an outlaw, a rabble rouser, or yes, tactician, everybroad type of warlord should be
capable of leading from the front.
The idea of leading the attack being a tertiary thing that only 1 or two subclasses get is just...absolutely bonkers!