They won't.

Their squad is better than ours and also better than the other clubs you mentioned.

I don't think any of the clubs you mentioned will be in the top 6 this season. Every season people think that Everton, Leceister, etc will be in the top 6 (like last season) and it still doesn't happen in the end. At the end of the day, the "worst" of the big clubs in the top 6 are still consistently better than all of the aforementioned clubs. Not only that, but do they obviously tend to have better as well.

Maybe I'm being pessimistic, but I'm quite confident the top 6 this season will be more or less the same as last season. Even if say, Utd finishes 5th or Arsenal 6th (obviously I don't know what is going to happen, just an example), the core will remain the same as last season. That's just my guess anyways.