Well, as a World of Warcraft player, "wipe" means when your whole team gets killed by a boss or an extreme amount of mobs. In other words, wipers are Pokemon that can kill your entire team if you can't stop their speed and attack.
Tbh I never saw Pokemon like a game of tactics.. the tactics you can follow are very limited to standart attack and defenses, moves, etc. If you ever play a (real) RTS game, you'll know what I mean.