In game, that strategy pretty much sucks. Why would yo spend your time making that strategy when you could be grinding?
In competitive, that strategy is pretty much ruined up, phazers and hazers are everywhere in competitve (especially in Standard) with moves like Taunt(that doesn't let you use boosting moves), Haze(Eliminates stat-changes), Whirlwind & Roar(These are the main problem, you've already [somehow] setted up your mighty 893 Attack and 754 Speed Rampardos with help from your Ninjask, and a Skarmory comes in and uses Whirlwind. Fin.
Unless, of course, you have a Suction Cups Pokémon (Octillery & Cradily); but they're not worth the pass, one is pretty frail (Octillery) and the other ones is killed by STAB Technician Bullet Punch or STAB Ice Beam; pretty common moves (Cradily).
Of course, If you're battling with your noob friend that doesn't know about pseudo-hazing and taunting, then you're lucky. I love killing my friends with things like 999 Attack and 999 Speed Magikarp or Dunsparce xD