Sledge is all hype and intimidation.
I figured out exactly how to get past it, and felt so stupid that I didn't before.
Any non-projectile hit > Sledge.
Seriously anything can work, 5A, 3C (recommended), even fucking Ice Cars beat Sledge.
My issue was (won't mince words) I was scared to get close to Tager, because who feels comfortable being that close to that infuriatingly lovable robot beast? So when my friend start sledging through all my shit, I panic.
When I was playing Arakune, I use 2C to get by it and to set up for curse, then it hit me.
So now I easily punish Sledge when recklessly used. I found that Jin's best remedy is to punish Sledge whenever possible, which is basically free combos, and try to sneak in an anti air (with Invincibility frames) when he tries to rebut your advances.
The fight is still mad hard, but now I'm starting to loosen up and win some matches other than getting 5 rolled.
(I do best 5/9 with friends)