CreamCloud0
Hero
it's the 'only the battlemaster can parry' problem, maneuvres are close to exactly this system(or something very similar) already but it's Been Decided that unless you take a feat only one class can do this thing and only one subclass will ever really be vaguely good at it, martials have had their abilities sectioned off as class specific things, For The Theming, and it's bad for them, only the monk will ever have natural bonus movement and actually good unarmed attacks, because those are Monk Things, and we'll never give them second wind because that's the Fighter ThingWhat I think D&D really needs is a robust but easy to use framework for basic action hero stunts. Jumping over enemies, throwing them at each other, sliding under them etc. It can be ability check based, but once you have the framework, then you can give martials features that interact with this system.
IMO martials really need two things: they really need to pool all their resources together to mix and match them as apropriate and they need to mess with the base mechanical structure of the game more: give them more action economy, expertise on attack rolls, more proficiencies in saves, those sorts of things.
and i've said before in these threads, there outght to be some spells that are replicable with skill checks, not all spells of course and with a few tweaks, but you're telling me identify couldn't be achieved with an arcana check? or disguse self as a deception check? find familiar as animal handling? cure wounds with medicine?