i started offline (pc version) did the first campaign for security, then did the objectives (at first all but be more objective **) went online and played around till lvl 10, then went back for (be more) and managed to beat it after about 4 hours spent on it (RAGE)
now i figured I'd go back and finish the campaigns. second campaign for security, my team ai gets the data key, then they all split up and take different routes (and get killed) i try to follow but the carrier runs full steam into the enemy before i can support him and take down the enemy ai
next pass i let them get the data key (because they take it before i can) and i camp the safe so i can pick it up the next time. when i get it, me teammates run full steam away from me as if i'm about to explode
upon the multiple times trying run the key i'm noticing my team ai engineers have been placing turrets in completly random location
also, turrets are messed up and dont shoot anyone
was doing everything on medium, set the mission to easy to see of that helped, no effect
Normal difficulty.
Medium body because I hadn't unlocked Light yet, and am terrible as a heavy.
Level 6.
I won that mission first time. It was the third run before I managed to actually get the data to the terminal, the first being taken by an AI because I got incapped in front of the objective and the Soldier who was "guarding" me decided to be helpful. A friendly Medic came to revive me instead of escorting the important guy, so I got back up about the same time the case was returned - jackpot! until I ran headlong into the entire enemy team... Oops. Mossington was my friend as a Medium, and even moreso in this mission. The reason the 3rd run succeeded was a combination of a well-timed Health CP capture by a friend, a fresh Health boost from a Medic, and the fact that I now actually knew where to go.
Anyone gets in your way, back up, wait behind the corner with your shotgun. If they cut the corner close, knock them on their backs and step in for the melee before they know what hit them. If not, 2 - 3 blasts should still put them down. duck back and reload in case more enemies come, and be prepared to slide and evade LOTS.