Going into the international break after 7 gameweeks it's interesting to note that the "Big 6" have quite obvious structural issues!
Manchester United
For all their "thumping of the minnows" I think United haven't been tested yet. Their average opposition stands at 15.4 in the table which is not that challenging for a team that costs in excess of £400M! The most obvious flaw in their line up is the presence of Matic and Fellaini in the midfield, which in the absence of Pogba don't really aid free flowing football.
Manchester City
Playing with just one central midfielder as the fulcrum with 5 attacking players, City at some point could be exploited by an opposition of three midfielders and some form of unconventional attack.
Chelsea
Chelsea play a 3-5-2 system which is asymmetric to the left side as Alonso is quite often eager to switch places with the left winger. They also have transitional issues which were on display against City.
Arsenal
Wenger has created some sort of Frankenstein football team with Arsenal. They have midfield frailties so they went to three at the back but a lack of decent center backs has left him head scratching so he uses whatever spare parts he can get his hands on to even the odds. With Kroenke trying to buy the full stakes from Alisher Usmanov, the second-largest shareholder and important players' contracts expiring, it's a mess at the Emirates at the moment.
Tottenham
Adding an unnecessary 3rd center back to arguably the best defence in the league at the expense of their midfield and attack they could have problems going forward in the coming months.
Liverpool
Well, "I can score more than you" had to stop working at some point of time and it looks like it has. With a defense that won't last even in the championship, Liverpool attack has to bear all the burden of winning the game and with a fixture list as busy as ever it's not sustainable.