I was talking about how they're performing as a team rather than individuals. Leicester are pretty lucky to have the points they do so far; Chelsea aren't
From FBref.com .. Leicester Goals For 29 / Goals Against 8
xG for 14.0 / XG Against 11.6
Its ridiculous to run at double your xg - everything they're hitting is going in (not just Vardy) ... its not remotely sustainable.
They're an above average team in the league just not close to title contenders, solid top 6.
Chelsea by contrast - Goals for 27 / Goals Against 17
xG for 23.5 / xG against 13.2
(they're a shade under 1 goal in xg difference per game - for context we're bang on 1 so their performance has been really good)
From a pure performance level, Leicester are worth their points so far (as are Chelsea, to be fair). They have the league's top scorer, and the best defence, while Chelsea have the second-top scorer, but the 6th worst defence. There's definitely over/under performance from both teams, but I shudder at the "unsustainable" tag. Not because at some point elite performance will fail (it almost will by definition), but the timeline of when that will happen seems to be referenced in the near-future, and sometimes that doesn't happen - largely, in my opinion, because the average game is 50% skill and 50% random chance, and the development of skill skews that ratio towards less dependence on random chance, which makes overperformance more sustainable over a longer block of time, than reliance on chance (which - to my interpretation - is why "possession" teams have more longer term success than "long-ball" teams, because the "possession" teams look to reduce variance).
I think it's a wait and see thing. Chelsea are running at a reasonable 2.96 shots or target per goal, which is close to average, so there attack is probably more sustainable in that sense. Leicester are running at 2 SOT per goal, which is better than even City's. But the question then is - A) how MUCH of a reduction will Leicester see, and B) how much will Chelsea's defence ultimately impact their league performance?
I think both teams are in a good spot, but also are vulnerable to a downturn in results. I'm not sure one is necessarily better-placed than the other to avoid it.