Not to sound like an -blam!-, but following people and trying to learn by observation isn't very helpful. Speak up and ask what you should be doing, even if you're afraid of being kicked. For Harrow pick a room and wander around til you get full buffs, then hit the switches in said room. If switches aren't done do another room. If you're doing challenge mode stay in the hallway til you have full buffs. Do a different room than your team mates or you wont see the purple screen indicator that he's chosen you to sneak up on. For damage don't lead him to generators unless your team mates are. Some people like to save them to extend dps timer.