Sure, here's some teams without the stuff you mentioned:
Maybe these aren't the best teams, yeah, but personally for me I enjoyed building a team that works for these bosses that can finish them as quick as possible. Ofc i'm going to reuse Pokemon that I already have, but that's not my point. My point is teambuilding for these bosses aren't as restrictive as you make it to be, plus it's not like these are extremely specific gimmick teams. As an example look at my Brock and Koichi team, you could switch any of the last Pokemon or rain Pokemon out for anything else, the main focus on Brock's team being the rain helping you.
Only time I mentioned the actual bosses in my reply was at the end where I said bosses are as fun or boring as you make them to be, never said they were well designed.
So please help me understand this. You don't like Hard bosses because they force you to use gimmick teams. I gave you some teams showing that they don't, but you said they were basically using the same gimmicks you disliked in the first place. Okay so make your own. Right but these boss Pokemon are gamesharked and the rewards are time-gated so you gotta make use of your limited chances. Okay, there's all sorts of resources you can use, the Wiki, a damage calculator, other people, before you make and test the team, right, cause you're not going to get it the first time. Ah but most people would just recommend the same gimmick teams. ?
Respectfully, you're not even making a suggestion in your first post, you're just asking whoever made the bosses to come up with something different. The dungeon thing is a great suggestion from Tora, but these too have buffed up mons. : (