SkillSystems for FE8U has a StrMag split, so it certainly exists there. I’m not sure about having it as a standalone hack, but I know that skillsystems without the skills displayed on the stat screen exists by Runa iirc (and with that you could simply give all units/classes zero skills). I’d suggest installing skillsys and running a custom build to revert the stat screen to normal.
Try learned level as 20 or 21. I’m not certain how it works myself, but I vaguely recall someone explaining it before.
If you can’t figure it out, perhaps you should ask on the skillsys thread. 7743 did not make skillsys, he just made an easy to install patch of it for febuilder.