How stronger would non-magic classes need to be to allow broad-non vancian magic?

[False God]

Add a "Stamina" system that gives martial-types access to a point-based resource which lets them perform maneuvers. (and don't lock it down to near-uselessness like Ki)

Yes I'm talking about Elder Scrolls.

Power Attack, Cleave, etc...all immediately become "abilities" that martial-types can use assuming they have the Stamina points to do so. No feat-taking required. OA's burn Stamina points, take as many as you have points for. Bull Rush? Sunder? All point-based. No I don't have a system worked out for this already.

Fundamentally there will still be things martial-types can't do. Flying. Teleporting. Summoning stuff. Polymorphing. It's all be about beating the snot out of other people faster and more efficiently. But they'll still be missing out on the truly powerful magical stuff.

Power comes from versatility. The spell-point system makes casters more versatile. Therefore it makes them more powerful.

Short answer: Much. They'd need to be much stronger and much more versatile. See: Tome of Battle.