Be extremely careful with your positioning! Grover has very good anti-sniper capabilities. You don't want him to notice you first. Remember about stealth, move and look around often to avoid a nasty suprise which is an axe hurled from across the map.
No matter if enemy Fernando is an Aggressive Nando or a Defensive Nando, even one good Wrecker dealer can easily disrupt both of these strategies. You reduce his teamwork, self sustain and disrupt abilities.
Nearly every Barik out there has a healing card in their loadout. It provides him a heavy sustain. Cauterize is an all around counter that also works against him very well in that aspect, even without a healer on enemy team!