It'd be better/easier to just increase the damage boost of WM to where you're actually matching the DPS of a "pure" DPS but make it so you can't play Ballad/Paeon during it so that you act like a pure DPS for the 95% of the time when you're not pushing your limit in progression and don't need the regen songs at all (like pretty much every dungeon outside of whatever the current very end game is at the time).

Then when you do actually need Ballad/Paeon, since you wouldn't be able to play it with WM, you'd take a severe DPS hit for the duration the song is up so you're not all OP and junk, giving everyone infinite TP while thrashing the DRG's DPS.