Thomas Shey
Legend
I think randomized resources are under explored in TTRPGs in general. Something like the ToB Crusader, who doesn't know exactly what they'll have at their disposal round to round. Unfortunately, they kind of design doesn't play well without hard combat/non-combat delineation. You could maybe use something like 13th Age's fixed number of encounters/triggers before resting, or FC's fixed "Scene" refreshes, and then lean in to different systems to offer players semi-randomized resources within those. That gives you big nova-level abilities, no real incentive to save them and a puzzle to figure out between refreshes.
Of course then you'd have people really soggy about the (admittedly) gaminess of the rule (as happens with the 13th Age case). That's why I say this is so intractable; there's a set of desires in play that are, fundamentally contradictory, sometimes on the same people. And solutions satisfactory to some are not only suboptimal to others, they're sometimes actively offputting (the round to round thing you mention with the Crusader would drive some people absolutely up a wall).