Biggle's right. If you play Impossible mode + Die Hard Mod, u can't survive without a scout. By the time your sniper spots the enemy, they're within grenade range and ur sniper definitely do not want to take that shot. Personally I use grenadier as main hero.... yup, he sucks in hiding. But who needs hiding when he can hurl a lite grenade almost over the whole screen(fully zoomed out)!