Medic weapon recommendation
Main weapon
Assault shotgun: high burst, high suppression, can penetrate the monster and does not consume blue.
All aspects are very suitable for doctors to go alone to protect themselves and provide objective output and suppression in the middle and late stage.
Side Weapons
The Freeze Gun: This gun wastes bullets very quickly and requires constant fire to maintain the freeze.
So you need to know when to use it correctly, and using the Freeze Gun is a waste of ammo if the monster suppression isn't full.
Analysis
Doctors need to go solo a lot of the time, so they need a primary weapon with instantaneous firepower to handle emergencies.
The Doctor's weapon grid is small and doesn't have a lot of options, and the secondary weapon only has 3 slots.
The doctor is usually the only character on the team that can freeze monsters (except for teammates with liquid nitrogen grenades), and usually carries a freeze gun as a secondary weapon to freeze bosses, or to provide a freezing effect when you want to capture monsters.