X Caliber, although I'd like to only need to use 3 pokémon of the same type as my e4 I think that banning pokémons because theu can one shot your team is lazy and stupid. If you see your team has a weakness you should try to get pokémons that can counter it instead of just saying "nope, change this one specific pokémon because its not fair". Also, some counters don't need to resist a certain type. If I battle you and you notice that my team only has physical attackers and you bring 3 counters + a Sableye I'll consider the Sableye as a counter as well and neglect the challenge. You don't need to resist a type to be able to counter it.
I couldn't agree more. Even outside of the league you'd need to balance your team in terms of strategy (i.e having not too many physical sweepers, walls, fending off likely threats, etc.). In a sense being a successful Gym Leader is extremely difficult, as you have to make a mono team work while being able to counter weaknesses. As for my Ghost Gym, I'm constantly thinking how I could improve upon it based on the strategic weaknesses it has, and I can only say I've learned a lot so far.
As for 3vs.3, I don't find the idea bad but on one hand I love being able to show off many different types of Ghosts, and on the other hand I think it would be more difficult as it allows people to use a full counter team in the 3 they choose.
Challengers name: Cryuel
Gym Title/Owner: Electric/Sito
Generation: 6
Battle Result: Loss 0-2
Rate your performance: 7/10
Rate opponent's performance: 7/10
Opinion about the match: Sheesh, frozen and paralysed a bunch of times, couldn't have asked for worse situations to be a sitting duck, lol. gg!