When dealing with armor and Hydraulic weapons some times it pays to think outside of the box. With Saint I looked at the maximum height the beak Of Tiberius could be raised, and then made the robot that bit taller, Problem solved.
also it can only chew at the edges of most robots. because the tip pressure reduces with distance from the fulcrum. the beak arm has a short reach.
Axes are harder the way I reduced the damage from them, was conveyor belt wrapped round the body of Saint, this has worked for years.

The lesson
Know your opponent. design round their weapons.