I res kill with sniper, shotgun, supers and grenades. It's all about timing, and if you hit the timing great. If not then you're in trouble. Honestly I don't see the issue. All you have to do is just run in front of your team mate or slide and push them to disrupt the shot. It throws the auto aim out if whack. I've even jumped and body blocked somebody. There should be consequences for just resing a teammate and not paying attention to your surroundings. It's fine as is.