The Viz scan suggests that the prime Juubi can carry mountains.
You know who else can carry mountains? That is none other than Sun Wukong.
Sun Wukong with his Ruyi Jungi Bang staff can carry mountains.
Hiruzen's character was inspired by the monkey king Sun Wukong, obviously.
Kishimoto is known to use many Asian folklore in his story, so comparing Hiruzen to Wukong is 100% legit.
1. Prime Hiruzen can possibly carry mountains with his staff.
2. If he can carry mountains like the Juubi, thus prime Hiruzen might just be on par with the Juubi.