Just a Razer/Tiberius kind of hydraulic piercing arm takes a lot of weight.
Tiberius IV has the mayor advantage of being 4 years younger than the latest Razer incarnation.

Now, the idea on its own is not bad. Hydraulic spreaders do excist. But with 10kg for the spreader alone, and the rest of the weapon, capable of piercing the opponents armor- take 3.2mm Hardox as common- you will have to get some weight from drive, armor or weaponspeed.