When you have a lot of attacking boosts, you don't need power. You need something that hits all of the relevant targets consistently. The reason not to use psychic is that it does no damage to tyranitar and sableye. Thunderbolt is the next most powerful option, and the super effective hits it gives are a nice bonus. The power of Thunder vs Politoed and Tornadus is totally unnecessary, and certainly not worth the inconsistency against everything else.
I am happy to mention Thunder, but only to explain why you shouldn't use it. Bearing in mind that Thunderbolt is only in AC anyway, this seems a bit too much detail to me.