First of all, thanks for the feedback!
Spell points grow much faster than exertion pools, and are both short rest resources.
Absolutely true! Here's the reasoning behind it to see if I can change your mind about potential balance. Using spell points to fuel maneuvers has an analogue with heralds using spell slots to fuel maneuvers, so this idea already exists in A5e. Both heralds and warlocks (if you used this archetype) can get a significant amount of exertion over other martial classes, but it comes at the cost of their spellcasting, which, as a full caster, is a bigger sacrifice for the warlock than the herald.
However, I do think there's a potentially strong argument to increasing the spell point cost to activate maneuvers—maybe it would be more balanced to have to pay the exertion cost of a maneuver plus one, in spell points. That way the cost of a level one maneuvers is analogous to the cost of a level one spell. I hesitate to do that, though, because then the dread knight warlock would be able to use significantly less maneuvers per short rest
and it would eat up all ability to cast spells. Here's a comparison between warlock and fighter:
Level 1: Warlock has 2 spell points. Fighter has 4 exertion points. Warlock can do half the maneuvers the fighter can do (even less if you make the spell point/exertion conversion worse), will have less hit points, and may have worse armor, depending on which Hell's Armor option you choose.
Level 2: Warlocks and fighters are now tied in spell points/exertion, but if we increase the cost of maneuvers warlocks still do less per rest and won't be able to cast many, if any, spells.
Level 3: Warlocks start to pull ahead of fighters in spell points versus exertion, but they also get more expensive spells that they can't cast if they use exertion. Meanwhile, fighters are getting other abilities that don't cost any exertion. (Warlocks might be in the same boat depending on how they manage Eldritch Blast and invocations.)
I think a better comparison is the adept, a class that gets bonus exertion but still won't get as much exertion as warlocks get spell points. The Adept also has the same HP as the warlock and more comparable AC to the dread knight, particularly if you choose Eldritch Armor. But then again, the adept only uses exertion for martial abilities, while the warlock has spells as a main class feature that it needs to balance against maneuvers.
In my mind, the balance comes from conceptualizing a dread knight's maneuvers as an extension to its spellcasting—kind of like more spells known, these ones just require a weapon in hand to cast. The dread knight doesn't give the warlock more resources to use, just more ways to spend those resources.
Of course, without playtesting, I can't be certain which direction is ultimately the most balanced.
Anyway, thanks for making me think this out a lot! Your comments made me directly compare the warlock spell point progression to the exertion progression of fighters or adepts, which I hadn't done before, and I think it improved my conceptual image of this archetype, even if I don't feel that it needs to be changed—yet.
And compare your eldritch smite feature to the Brute fighter’s.
Thanks for the comparison! I had forgotten about the Brute fighter ability that's analogous to this. That actually makes me want to increase the spell point cost of the dread knight's smite across the board because, unlike the Brute's ability, the dread knight's smite also knocks enemies prone.
