Thats a way, if you have Lilac simply put the squad with Lilac in top with a VERY fast helper squad. Lilac squad will clear the pest far away, helper squad clears the other pest.
For the ?-4 I'd advise a 1-1-0-3 approach. You need 3 squads top right to get the pest. The last squad to move should NOT contain Lilac (the third squad is the one that will make it to the pest and shortcut)! Otherwise she'll reach the boss too early. Play around a bit with the movement speeds required, failing on these event maps is not so bad, the bosses and garden spawns are great. You might even find an Ampy on the map as well.