2 of the end tree talents can be focused around being only able to equip ranged or melee.
Melee could be something like a 2 handed great sword where maybe you can block with it and shield yourself from some bullet fire, but otherwise you just clean up in melee range.
Ranged only could be a better infinite ammo set up so you can just constantly let loose a machine gun.
The third end game tree could allow you to equip a ranged and melee weapon (although not the 2 handed sword or bigger machine gun) and be something maybe focused on tanking.