No it’s not normal that they see through the map, maybe a balancing factor. But a melee kill through wall is definitely bad.
I’ve seen yesterday a twitch session where the guy was complaining at least a minute about how on earth was the opponent able to spot him and shoot immediately when he sneaked at him from above & behind in Berlin - for which the AI modification @119637827 mentioned could be a reason.
I said that it is normal only because AI being poorly educated by developers, the only way it has to be competitive is to cheat as in the aforementioned way, not because I believe that AI should be like this, indeed quite the opposite if it were like the AI of modern FPS there would be no such problems and you could safely play enlisted without worrying
Ok, I fully agree with that. 
you had an great idea, also for expand i have the idea of give specificall defence positions to the bots like Company of Heroes, where you show the bot where to take cover, and also when the game detecs you are in a interior (example house, bunker, ruins, forest…) the bots automatically get into the house, i hate when i’m holding a position and even with deffence order i see my whole squad just leave the bunker in normandy in middle arty attack
[sorry for spelling mistakes, etc… english is not my main languaje]