>>17819496It's impossible to have your in game bro's have perfect IV's unless you bred them before playing the game. EV's though, are still very much a possibility. There's blank bags to be found in the supertraining mini game and perilous soup to be had in the juice shoppe. Both of those reset a poke's EV's to zero and enable you to get perfect EV's for your bro's. There's even an ability capsule to be earned in the battlemaison if you happen to have a bro with a bad ability!
You might still be at a disadvatage to IV bred pokes online, but it won't be as bad.
There's no shame in using the post game options to get the most out of your bro's. It's what I did and even I manage to surprise people with my in-game team every once in a while.