That was a really nice kill but you basically got super lucky in the first mine being at camp spot, if the first mine was at the other end of the map you would have wiped. I mean even the guy running to the first mine spot got killed by all the wire snipers and arc shanks, if you hadn't killed the boss the second guy running to the mine spot would have died in the same way.
Well actually our guy running to the second mine died and resurrected, that's why it worked so well. He started running basically when the first mine popped anyway, the two titans took care of the first mine. So we actually didn't send a second guy to the mines so we were fine the whole time. So you really want that Warlock running to the mines so he can wipe and still be fine + have the extra armor from fireborn. We definitely could have taken him down faster too, I missed some snipes and I could of kept sniping instead of using Thunderlord but since I'm not a good sniper I'll take the guaranteed 30k damage from a thunderlord clip.
Edit: Patience and Time won't do it. The extra 2k damage from 16 rounds from 3 players adds up to a lot of missing damage. Not to mention two of us had final round so when I did land a crit (I'm a shitty sniper) it hit for 11k. It's a shitty requirement but at least it is more attainable then needing three gjallahorns
P.S.S: Unless you meant that you have to burn him down by the second mind regardless. I think that is true, if you don't have him down within 30 seconds of the first mine popping you mine as well wipe. It is a very all or nothing strat.