Yeah, Zaraki can't take nearly the same amount he can dish out (Country busting attacks), Sasuke is far smarter, versatile, and had the power needed to put Zaraki down. He can place him in a genjutsu, not one that would immobilize him but similar to what he did to Danzo to go for an Aizen-like effect and trick Zaraki. In addition, perfect Susanoo is very powerful; it was chopping up pseudo-meteors like no problem well before they hit the ground. Zaraki can one-shot Sasuke but it wont happen since Sasuke is too fast and has a variety of told to keep distance or avoid getting hit such as genjutsus, rinnegan, clones ect. Zaraki is the better fighter but Sasuke is the better warrior.
Sasuke because Perfect flying Susanoo is country buster level. he has the speed advantage here (Ken shouldn't be able to keep up)
Sasuke has Sage black Chidori and Rinnegan with a lot of abilities that has yet to be seen. Kenpachi has Shikai which is at best island or +.
Their is also Sasuke's Teleportation abilities and Chidori sharp spear that was powerful enough to cut Madara in half, something that Gai failed to do in eight gate mode.
It seems like you're downplaying Bleach a bit; the meteor was going to destroy the entire Serietei, that place is huge, a meteor that size would wipe a good portion of a large country off the map let alone one summoned by Gremmy. That meteor was far above city level, that was a small country level feat at least.
The meteor wasn't country level, it wasn't even shown to be that large and only displaced enough weight to destroy the center of the barrier, plus Seireitei isn't the size of an actual country, I've debunked this in another thread.