What I'm getting at there is that Exploits and Spells were the same mechanic with different set dressing. There's a lot of spells out there that could just be martial in nature, but there's also some that might have desirable effects that are more supernatural...but just like artificers justify their effects as being object-related, a "warlord" could justify their effects as being mundane.
The
vast majority of spells are completely unacceptable unchanged. Period. They would need to be changed so significantly, they would be barely recognizable.
They cannot have any components, especially not material nor somatic ones. They cannot permit being counterspelled. They cannot cease to function in certain areas because anti-spell effects are in play (AMF, dead magic zone). They cannot involve the
vast majority of nonphysical damage types unless fueled by an actual material, e.g. if you bring along a bottle of alchemist's fire, then sure, that could enable fire damage, but unless it's psychic damage I'm not buying it as a martial action.
So, what does that leave? Even if we pretend that all spells are suddenly immune to
counterspell and AMF/dead magic/etc., and allow not just psychic but also force and thunder damage (because I'm feeling generous), I'm counting a grand total of 16 damage spells and 31 non-damage spells. Of the damage spells, the only ones I can even remotely justify are
sword burst, ensnaring strike, thunderous smite, wrathful smite, zephyr strike, and
staggering smite. You may notice that most of these are Ranger spells, and most that aren't are Paladin spells—and are basically just psychic or thunder damage riding atop "do a weapon thing", "scare someone badly", or "push someone around."
Utility spells are even worse. The only ones I can see passing muster are a few heals,
hunter's mark, command, and
knock, with nothing above 3rd level being even remotely acceptable. Perhaps a dozen spells,
max, and even those would need to be reworked to some degree.