it would be interesting to have a tournament with other trainers before we get to the e4. might be easier to implement as a "tourney" meaning that the string of tariners and whose outcomes were predetermined, having it look like an actual battle. You would just need to program the trainers who you battle rather than force you to sit through a battle like that! XD
It would be interesting. But considering the strength of the trainers that have gone up against the elite four, I wouldn't be surprised if we did implement that system the E4 would be full-on competitive (Items, competitive movesets, max IV+EVs, good natures, etc).
I still find it kind of pitiful how Ash's pikachu couldn't even touch Diantha's gardevoir. and then face a team with three pesudo-legendaries + uber (Aegislash) + Mega Zard X with only a greninja left. I don't know how overkill it would be to put pesudo legends on these teams.