Not much versatility. 3 maneuvers is very little when compared to the spell list of a caster. They tend to have as many cantrips as that by that level. Like I said, I consider Riposte, Precision Attack, and Trip Attack to be such generally useful choices that you'll almost always take them (unless you're a bow-fighter, then you will likely skip Riposte).
See I disagree with you already... Menacing Attack...Frightened condition (disadv on ability checks and attack rolls & controlled movement) to me is a much better choice than Riposte, but to each their own.
As for versatility... well yeah, maneuvers aren't spells they are martial techniques and thus centered around fighting... so no, they won't be as versatile as spells... luckily for those who want spells we have the EK.
Finally if you want more maneuvers then there's a feat for that and it ups your # of superiority dice as well.
Consider. The Sword Coast Adventure Guide cantrips "Green-flame Blade" and "Booming Blade" are weapon-based cantrips that have effects that are very comparable to the effects you might expect to see on maneuvers, but they are at-will and having scaling damage. It's not a perfect comparison for a variety of reasons, but it's enough to leave a sour taste in my mouth. Sweeping Attack to Green-flame Blade. I mean, come on.
Surprise... surprise I disagree again... they really aren't comparable IMO...
Booming Blade
1. Limit you to one attack as they are spells not melee attacks... Maneuvers don't limit the # of attacks or how many times you can use them if an attack hits in a round
2. BB does an extra 1d8 dmg if the target moves... Maneuvers do 1d8 damage (superiority dice) + an effect without requiring the target to move
Green-Flame Blade
1. See above
2. Does extra ability modifier to a creature within 5ft of the first creature you attacked with it... Really, how about you use that maneuver that ups your AC against OA and dish out multiple attacks on both targets for no cost with an extra 1d8 dmg on each + effect.
I'm sorry but I'm not seeing how these are comparable at all...
Not as big as a gap as you might think, given the oft-quoted problem with bounded accuracy and ability checks. Being proficient in something doesn't actually improve the odds of success that much. In very extreme cases, like an 8 non-proficient vs. a 20 proficient, sure, there's a noticeable gap. But that's more of an outlier than a useful example.
No it's not an outlier when using the standard array... characters will have dump stats that have an 8 (like strength for a wizard or a knowledge cleric) and they will (for the most part) maximize their primary abilities like (strength/dexterity for a fighter)...So my point still stands. You claiming this is an outlier does make me curious though... do you think most wizards spend ASI's increasing their strength... and moreso to the point where there's little difference between them and a fighter??
I gave one specific example of such, actually: grappling. Grappling is not covered or aided by any maneuver. And it's definitely a combat-oriented concern. You could boost grappling and shoving by aiding Athletics checks related to specific actions (Grappling, Shoving, Climbing other creatures, etc), and it wouldn't even interfere with a non-combat pillar, though I don't think it'd do all that much harm if it was a general boost to Athletics.
Okay on the one hand you complain that too many of the manuevers aren't generally applicable... but then you argue for a narrow maneuver that helps a specific action... color me confused. That's exactly why I'm asking about design space. It's easy to create a bunch of narrow specific maneuvers... but is anyone going to pick them over the one's already there? Especially with a limited number? If not then it's just bloat if you create them.
Anything that would be hypothetically released at this point wouldn't be core.
Fair enough I thought we were talking about the BM in core... and what you would have liked to have seen. My bad.
Rogue and bard have expertise, which doubles the proficiency bonus to Athletics. Bards can increase their bonuses on top of this via Enlarge/Reduce or Enhance Ability, 2nd-level spells. Rogues have Cunning Action, which can be used to Dash, and therefore increase the distance you can drag targets while grappling (remember, when you have grappled another creature, you can move at half speed, and move the other creature with you). I consider that to be quite important because the grappler focuses more on controlling the flow of battle than huge damage, and grappling opponents so you can drag them over to a cliff side and shove them off, for example, is one thing you can do with that (or into pits, into harmful spell effects, etc). The barbarian can Rage, which gives them advantage on all Strength-related checks, including Athletics, and get a minor boost to speed besides.
Well first the Rogue would have to be proficient in Athletics... Then pick athletics as one of his finite expertise choices... his highest attribute is going Dex and second is probably Con so let's say 13 in strength for a +1... he's not going to waste his first 2 ASI's on strength, he's going Dex.. so at 8th level, assuming proficiency and a 13 in Strength he's got a +7
Meanwhile Fighter who has increased his Strength to 20 (+5) and has prof in Athletics has a +3 for a +8... o he's still ahead of the Rogue who spent a finite class ability to be a better grappler...
Now granted the Rogue could devote his first 2 ASI's and expertise and put his best ability score in strength... but at that point it's costing him so much that it's honestly not worth it... and even then he only outclasses the fighter by +3 and he's made himself a sub par rogue. I guess that could be worth it to someone... but talk about outliers.
I also don't understand why if you're bringing spells into it... you also aren't bringing maneuvers into it? You seem so focused on the ability check that you are ignoring the possibilities beyond that for a BM... especially since you can still attack 1-handed with a grapple.
All three classes have innate ways to improve their Athletics checks, and the bard and rogue have significant additional advantages besides that. The fighter cannot boost its Athletics check on its own, the best it can say is that it can Action Surge for additional movement/tries every so often, or it eventually scales up to a large number of attacks for more attempts to grapple (has to wait a long time for that though).
The question isn't how much can they improve their athletics... it's how many of these resources are they spending to match or barely exceed the fighter's natural ability?
I would not say the battle master is bad balance-wise. I do think it's a bit weak, and I think it'd be evident if, say, I were to temporarily allow a battle master's superiority dice to recharge at the start of each turn. As far as the dice recharging at the start of each turn goes, it was actually like that for a significant portion of the playtest, and didn't seem to break anything!
But that's just a thought experiment. Maybe it would go horribly wrong. I doubt it, but maybe.
I would say alot of the Battlemasters "power" comes from creative tactical usage of his maneuvers... If you're not using them strategically with the others in your party then you probably come off a little weak... on the other hand if you're maximizing them and coordinating well with your party... you can be a real powerhouse.
I'm not proposing any more "fiddly narrow options" than the spell list provides a full caster. I would actually use the EK or perhaps Paladin as a baseline if I was to design the class myself, but with its own list instead of simply drawing in a limited form from the wizard list (or having the paladin's focus on buffing/healing).
But we have a fighter who draws from the wizard list... the design space has been used and it's in the core for anyone to take... why do I want a(nother) fighter with spells... that aren't called spells?