Get a minesweeper.
Aah this reaction is so 2014. At some point you can't have 3 sweepers on all the sides of the map. Unfortunatly for you all my pio's of RE got sweepers as soon as possible. This doesn't mean that you can cover the whole map. Sometimes you want to try to flank and also calculating some risk of mines, but getting a full squad killed by a 30 muni mine is then pretty fucked up. The investment is too less to get that much effect. Same can occure with trip wire flares or S-mines.