I don't know. In CS:GO, there's almost no point in the game where you are constantly shooting at each other with no armor. (90% of normal game, every other gamemode) Personally, the charm of this mode for me is no armor. All the guns essentially get a damage boost and feel more LIKE guns.

However, if there is going to be armor, it should be rewarded, not given. If it's late game and there's just a sea of guns, you just take the class that gives you armor and steal the weapon you really want later.

and more class ideas, we have a long-mid range class (SSG 08), mid-short range (MP7), short + mid range (MAG-7 + P250). Mabye a grenade focused class (Molotov, HE, Decoy, Smoke + Glock-18)