As a medic, you’re gonna be in the poop a lot. A long range weapon is not the best idea. A drum magged SMG is the best choice for a skinny medic. Engies are the best with the sniper rifles as they can double buff the gun to make it a killer.
On a light, you may wanna use the Drognav so you can shoot a bit faster, which is good when you’re in a closed indoor map without many sniper advantage areas. But a double-buffed Barnett in the right hands is deadly and a great support weapon during a big gunfight. I liked using my COGA scope Barnett mostly to support my team in a battle picking off enemies from far away. It is not a great solo weapon as it is not a one shot kill on a full health target, (except light/medium heads shots on non buffed players?) But if your teammates have already popped a few rounds into an enemy during a big battle, it’s a great finishing tool.
I switched to a medium while using the Barnett so I could make it my 2ndary. Much better to have an automatic weapon as an option if things get hairy.