My favorite strategy is to start by going to the power ship, one person heads toward juggernog while the other flips the power, both players grab juggernog and head towards the lighthouse.
One person lures outside the lighthouse, the other inside.
Keep doing this till about round 20~25ish when it starts taking a bit for the rounds to end, grab a scavenger and work the lures so that the inside guy
Brings his mob out to collect with the outside guys mob, fire a scavenger shot and move back to your respective spots.
I find this strategy works well untill upper 50's, Then switch to a PaP'd VR-11 and do the same as before except hit your teamate with the VR-11
(Once as it conserves ammo) Your teamate then throws a grenade, etc. killing the mobs, return to lure spots and begin anew!
This strategy got a friend and I to round 85 you should be able to do the same given some practice.
Good luck and have fun!