Discourage enemies from moving.
Sentinel Feat.
Force an enemy back with a fierce attack.
Pushing Attack or Tripping Attack
Frighten a group of lesser enemies into hesitating (not moving or not attacking on their next turn).
Menacing Attack
Alert Feat.
Coordinate volley fire or a formation attack (possibly of NPCs), resolving it quickly like an AE, instead of each subject (or the DM) rolling each attack individually, and make it more effective than the individual attacks would have been (again, especially for NPCs). (It's the old, train the villagers to defend themselves thing.)
Maybe something for mass-battle if they ever finish the BattleSystem rules. (Though I'm loathe to give a class any feature that makes a necromancer's skeleton horde even MORE deadly...)
Use a reaction to bring an ally to his rescue when attacked.
Commander's Strike, Maneuvering Attack is pretty similar.
Tricking an enemy into a 'false sense of security' so it's initiative is delayed, or it doesn't take critical action immediately.
Confuse an enemy, lowering his initiative, or limiting his actions on the next turn.
Draw an unsuspecting enemy out of position.
Trick an enemy into a trap or AE of an ally (ok, the second part is kinda support).
Take a command from a Boss, causing a lesser enemy to take an action of his choice
These sound like they could be handled with a good Deception Check.
Drive a wedge between two enemies, so they attack each other.
goad/trick every enemy w/in 10 or 15' to move adjacent, then whack 'em all with one great cleaving blow (or a series of quick Inigo Montoya thrusts).
Come and Get It should remain buried (under 20 feet of concrete) but if you really want to, Goading Attack and Riposte are there
Disarming Attack
Find a flaw in/damage an enemy's armor or other defenses
Find a 'counter' to an enemy's attack, rendering it less effective for the rest of the battle.
Trick an enemy into revealing a weakness, or deduce the weakness if INT-based rather than CHA-based.
These seem like Perception, Insight, or Knowledge checks to grant advantage to an allies attacks or learn known weaknesses ("That's a troll! ready the oil and torches") Barring that, Precision Attack, Evasive Footwork, or Parry.
Make a devastating 'Surprise Attack' against an unsuspecting enemy who thought he was just a caddy.
Sneak attack? Ok, maybe Lunging Attack (reach), Feinting Attack, or a really good Deception check for advantage
And, at the risk of causing some heads to explode: Pull a 'big reveal' where some 'plot point' or reversal of fortune changes things - an enemy is actual a sleeper agent that infiltrated the bad guys years ago, the ground in front of the charging force was undermined by deep gnome allies no one knew about, re-enforcement come riding over the hill. The whole melodrama thing. Yes, it's an /actual/ 'plot coupon,' and yes, it'd be double-dog/triple-pterodactyl, hidden in the Auschwitz of Option Ghettos, quick-avert-your-eyes, whole-table unanimous approval required, you will neverevereverevereverEVER have to put up with it or even hear of it actually happening if you don't like plot coupons, OPTIONAL. But it's fun at tables that can handle it. Some of them are even D&D tables.
NOPE!
There is NO quicker way to watch a class get banned from most table and in AL then "plot coupons." That is a DM table thing, not the basis of a core class. The hell that would unleash on the community would make shouting a ally back from unconscious look like rolling for initiative in terms of acceptability. Its a good option for a game, but a piss-poor one to build a class around.
That said, a lot of those things are already Battlemaster maneuvers or improved skill checks. The few that aren't could easily be added to the list. I get that people would want a warlord to be a tactical genius, but how many of these are either already maneuvers or just reasons to gain advantage/impose disadvantage?
The more I look at this, the more I think the battlemaster is doing a better job at this than its given credit for...