Ok so yeah I tested again and the problem persists(Rock Only Challenge)
So unfortunately this challenge is not possible without leveling up my Strength. The problem stems from the upgraded enemy types. They just love to soak up so many of my rocks. Then you have the ones that heal themselves if you don't kill them in time. This clip is an example, and that was after leveling my strength up by 5. Don't even get me started on the Guardian enemies.