Opinion about assigned gun classes

Hello, i had a little thought based how guns behave when a class uses not the gun that is assigned to it. which gives spread that breakes the gun because the class doesnt "know" how to control it. 

Starting with:

Recon- Recon is a sniper right? in some countries they use DMR's so they do know that field, so basicaly it should have it assigned too dont you think? Because its not assigned the gun's bullet spread is going basicaly bad, hitting clean heads is just desperate at this point.

Support- He has his perfect gun assignment but i think it should have shotguns too, judging by "fire support" he sometimes stay behind helping others and providing support at the same time.

Engineer- PDW yeah, close range combat. perfect to say goodbyes for sneaky people trying to c4 your tank. but shotguns should be fine too right? they should have perfect control of it too. 

Assault- class that i dont quite understand, it feels very forced, very focused on kills and CP's, providing fire power at the front lines, having two guns. I think i cant quite choose between Shotguns and Carbines, after all at the beta, shotgun was the third "gadget", but when it comes to weapons that are on the first equipment (not the gadgets). It should be Assault rifles and Carbines.

Its just a small thought, maybe im wrong, i just wanted to say my opinion which probably doesnt mean anything, just blabbing about guns... Well... just trying to get a answer that would just make me stop thinking about that... i dunno.  Please share your thoughts. Thanks a lot.