I try to kill everything as fast as possible. But I don't need to kill every thing. If it's in my way, it dies. If I have to hunt it down, or alter course to get to it and it's not a requirement of the Strike, I move on. I voted Runner, but more because I try to get things done quickly, not that I just dust my mates. If I see guys lagging behind, I'll wait for them, or kill enemies between us to help them get to me. Mostly, I find that other Guardians behave the same way. Kill it, kill it fast, get moving to the next bit as quickly as possible.