.........Man I must'a in a blind rage when I first typed this. Bad bad bad bad me.
That center is a trap, but only because it takes 3 whole teams to unlock it. And I misremembered where that trap was in correlation to the starting base.
1 Fast squad up north.
3 Neutral/Slow squads in the center.
1 Slow squad down south.
This way, you're pretty much guaranteed to hit everything from the center on down, left with a 25% chance to pray for that North squad to stay on track.