In Metal Gear Online you have four skill slots. What's the point in having a level 3 skill if your other skill is going to suck, and especially if you want your character to be dexterous. (If you want to know, I "Need" a level 3 shotgun [Please do not call me a noob over that, I already get that enough online] but I also "Need" at least a level 2 runner so I can run and hide like a coward fast enough and so I can quickly kill the enemy when I charge in because of the pump-action and semi-long reloading nature of the Shotgun)
