I think I have decided I rather like the Warlord as a Fighter Subclass it hearkens back to the 2e Warrior Lord descriptions of the fighter (The 2e fighter very much desscribed the fighter as both Weaponmaster and Tactician).
So I am not sure about this though it does evoke rather strongly both the 4e Warlord along with using Mearls happy fun hour: subclass as a starting point.
https://www.gmbinder.com/share/-L9FFfbsDApwhwdqDEJo
Any opinions?
Here is the transcription of the Happy Fun Hour design. Mearles video actually did mentioned building a Fighting style that felt Warlord Like but he didnt present one.
https://thinkdm.wordpress.com/hfh/warlord-fighter
But I actually thought of that.
Right off the bat there's no flavour. Most powers begin with a small sentence that describes what's happening in the narrative/ world. But this is a small sub-power so we'll ignore that.When an ally who can see you uses an Action to make an Attack, the ally can choose to take advantage of this feature before the attack roll. If the ally chooses to do so and the attack hits, the ally can either make a Bonus Action to Attack or Dash after the initial attack. If the attack misses, the ally grants advantage to all enemies until the end of his or her next turn.
Especially at level one where it gets a Fighting Style AND a Leader Style AND a Commanding Presence. Most 5e classes have a single small choice at 1st level, not three.
Okay, Tactician's Insight. Initially, this mechanic was balanced against the spellcasting of the eldritch knight, which is a 1/3rd spellcasting class (i.e. it gains more spellcasting every three levels opposed to a paladin or ranger that are half-casters and wizards or clerics that are full casters.
This class gets Tactician's Insight at 2nd level so it's a 1/2 caster now, and balancing against the paladin is the best baseline.
Right off the bat I can see it should get a third use at 3rd level, and a bigger bump at 5th level. In total it can use the power 20 times compared to a paladin's 15 spell slots. However, it doesn't improve, so it starts out pretty darn good and slowly falls away.
Having the level 20 capstone be a subclass feature is curious. I think only one other class does that. It's better to make the capstone iconic to the class as a whole than have to invent several high level abilities.
To get nitpic the language shows a very casual knowledge of 5e.
I don't see a list of Tactics nor a list of Tactical Gambits. Am I overlooking them or are they somewhere else or ...?
Despite how it displays, that URL seems to be a "mailto:". ??
Perhaps as a Fighter subclass it might even be able to just hand out its action surge to an ally. (not a big change in power)
Check out the Purple Dragon Knight from the Sword Coast Adventurer's Guide.

(Dungeons & Dragons)
Rulebook featuring "high magic" options, including a host of new spells.