I don't play Xin or Kayle because i want to. I play them because it's too optimal.

Thinking about this from a basic game theory standpoint, let's look at what happens with devourer jungler.

A devourer jungler basically has 3 outcomes. His lanes win, he receives his sated, they proceed to just rock the opposing team with the sated's DPS

His lanes ALL lose, he may or may not get sated, he still loses.

OR his lanes stay in the game, and he wins because he outscales the other jungler.

So out of 3 possible outcomes, the sated jungler is just already at an advantage because they have an insane late game to fall back on. They have little owness to do anything in the early game, just hope your lanes don't feed, collect crabs, ward, and powerfarm.

OR you can play Xin Zhao, have a huge impact on the early game, and still get your sated devourer. You're VERY strong early, mid, and late with the biggest dip in the early mid-game.

So what's the optimal choice against a Xin or a Kayle? Pick another Sated Devourer jungler. Looking at the matchups vs the other enchantments

Vs a Warrior: The warrior is on the clock from the moment the game begins. He has to completely destroy every lane or get one lane SO far ahead that they run the map over. He's going to get outscaled PURELY by virtue of the item he has selected. He must build a lot of damage to be able to erase an opposing squishy, because going tank will just get him melted by opposing sated DPS and AD carries in general. He's useful, but not AS useful as a tank and doesn't do AS much damage as a Devourer.

Vs Cinderhulk: The tank is already at a disadvantage, because they also want to reach the mid-late game where their tank items will have the most value and they can optimally use their abundant utility. However, sated and even non-sated devourer DPS can still melt him in the early-mid game, and a duel with a devourer jungler will result in death or at the very least retreat. Ironically, the Devourer jungler has the advantage early because their item is more efficient earlier.

Vs a Runeglaive: Some of these jungles actually can do fairly well, but will still end up getting outscaled. The only one that stands out is Diana, who has burst to pop a squishy. Elise will still get outdueled by Sated's that buy Sabre, as a good portion of her damage is diminished by the smite. Evelynn is far too squishy and not useful enough to warrant a pick against a Sated jungler, as she will also get outdueled and outscaled. A lot of times this is a fairly even matchup, but the late game will always go to the Devourer.

So if you have to pick a jungler against another Devourer, you essentially have to pick another Devourer.

Those that say that you should just "fight them in their jungle" are not considering the tools the Sated jungler champions have and the items at their disposal. A large portion of these champions are already really strong duelists and would not go down easily like Xin, Shyvana, or Udyr. Additionally, you're taking a huge risk wandering into their jungle. Many of them don't take much damage from their camps because of heals, sustain, or generally fast clear time. Any warrior is probably taking a beating because your sustain is not up to par. You're ALREADY walking in with a disadvantage. Skirmisher's Sabre INSTANTLY solves their counterjungle vulnerability as it makes them extremely dangerous in 1v1

Back to the title now... Why do i have rank 5 on Kayle and Xin? Has NOTHING to do with liking their champions or wanting to play them. I pick them because they're such an optimal pick and they're simply just better than ALL the other choices. It's essentially my responsibility in the draft to take them away from the opposing team because they're so overbearing.

But the champions themselves are certainly not the issue. Before the Sated patch, Xin was sitting at around 50.5% winning percentage and Kayle I believe was below average because she also didn't find a spot top against the tanks or mid against the mages. So while some people were glad to see Kayle come back, many will agree that when Kayle is strong, she's WAY too strong.

Looking to coordinate against a Sated Jungler is the only real option against them, however you can try your best to get that to happen in solo queue below Diamond 5. I'm willing to wager it won't amount to a reliable strategy.

TL;DR

Devourer junglers have VERY few bad matchups against other enchantments and if their lanes win, they win by default. If their lanes lose, they still have a good chance at the game because of strong late game.

Counterjungling isn't a viable strategy because the kits of the Sated users allow them to duel quite well, and when paired with a Skirmishers Sabre usually means you lose if you're anything but another Devourer Jungler.

The champs that use the item aren't the issue, it's the item itself COUPLED with their safe early game and dueling potential that makes for too optimal a pick.