Supposedly, the RNG is pretty terrible in this event, the previous event, and the next event. After that, things should get slightly more managable again.
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?-3 may take a few tries, but it's the one I'm farming, because the chests are easier to reach than the ones on ?-6. I put 2 fast teams on the left camp and 3 medium/slow teams in the right camp. None in the center camp, one of your fast teams hopefully turns in that direction.
?-6 is RNG hell. Basically, try to get your timing right with one fast team on the center camp and all your other (and noticably slower, like, 25% slower) teams in the top camp. Ignore the bottom camp, if your center team is fast enough, it should pass through that area.