Question about sledge hammer training

[Fist of Fury]

Hi everyone. I've recently tried some sledge hammer deadlifts with a coin on the head. I've noticed that lifting from the front is way harder and I assume that's just how the body works. I'm wondering what a normal ratio between front and rear lifts is. I can do about 70 cm rear and 45 cm front with a 10 lbs sledge. Is this difference normal? I want to make sure that I don't have imbalances in my arms.