Radec is the only "gun based" character so far... because he's from an FPS, what else is he gonna do? Throw fish at people? Get real.
Drake is from an action adventure game. Sure he uses guns, but he's got enough personality and melee attacks to keep it different to Radec.
Jak is primarily an action/platformer character, with guns implemented into his playstyle because he had 12 of them by Jak 3. The Jak guns are far less traditional anyway and offer unique and interesting ideas like playing with gravity.
Fat Princess has no guns. Kratos has no guns. Parappa has no guns. Heihachi has no guns. Big Daddy has no guns. Toro has no guns. Cole has no guns. Sly has no guns.
Sweet Tooth has a shotgun for ONE MOVE.
But wait! Everyone can pick up the RPG-7! This game is doomed!!!!!!