Stevens was a dwarve compared to GGG, so would Quillin be. Chavez Jr. at least wouldn´t be outsized. And as GGG is very hittable, this could be interesting, especially since Jr. can take a punch.
Chavez is "very hittable", GGG has a pretty decent defence. He got caught a few too many times against Stevens because he was a bit too concerned with his offence and thought he had him finished but, on the whole, his defence is okay. Jr's defence, on the other hand, could at best be described as porous. He's big and he can take a punch - when those are a fighters two best qualities, that should give you pause. This is the guy who was out-boxed and out-fought by Brian Vera!
Yes jnr would destroy GGG in being a drug infested lazy bum contest, but when it comes to boxing, I think GGG would have fun
So what, sparring is not the same as a real fight. One thing you cannot take away from Jr. is that he is coming for a fight. Look, what punishment he took from Sergio and then he almost got him out. Now GGG´s chin is probably better than Sergios, but on the other side he is way more hittable. I´m not saying Jr. would beat GGG, but he could make it interesting. At least he is not physically disadvantaged as most of GGG´s victims so far.
Golovkin can't fight going backwards and even though he was throwing alot of punches against Stevens i seen him breathing very heavy in the corner. I think Chavez's body shots would do alot of damage to Golovkin on the inside and Chavez would walk him down the whole fight.
I suppose it would be interesting to see if Jr changed his plan of marching forward all night when he's eating huge power-punches. You say that most of GGG's opponents have been physically disadvantaged but what about Jr's?!? He looks at least 2 weight classes bigger than most of his opponents and even after the debacle in the lead-up to the Vera fight where he was allowed to decide the weight-class on the day of the fight, he was still clearly (imo) beaten. I'd rather see Golovkin tested against opponents whose main attributes aren't "they're big and can take a punch".
It would be a good scrap, but triple G would win via TKO before the 9th. The Chavez corner would throw in the towel to prevent their man taking further punishment :deal