Yeah the 2nd mine spawns on the other side of the map... impossible to make it across in time without getting torn up by crossfire, even with one player running distraction and the other running.
I reckon it would be straightforward with a third player just camped out on that side of the map until that mine spawns.
Does it alter the number and difficulty of enemies depending on if there are 1, 2 or 3 players?
Try doing lvl 35 under levelled when destiny was challenging had to work together to complete it.
Once mastered could do it without a single wipe, round 3 was great fun and end fight was all about taking your time.