It's difficult to pick a first team between the two teams. The keepers are both the best in the Prem, but for me and many others, DDG is ahead of Lloris but he's also a fantastic keeper.
Walker burst on to the scene, but had a difficult second season and showed a lot of weaknesses while Valencia has grown into the RB role however he did struggle massively at first and is now the wrong side of 30. Walker has been solid this season, and was good last year as well so he probably has the edge.
Vertonghen and Alderweirld are the best CB partnership in the division. Even individually, they are probably the best. Smalling had a good season but hasn't featured much this time and has looked dodgy, however I still think he's a top CB but he's going to find it tough to get his place back due to the form of Jones and Rojo. They need to sustain this and stay injury free to the end of the year now to be considered as even near the best CB's in the league.
Bailly was fantastic before his injury but it's too early to include him in any discussion of best CB in the Prem, until he's been consistent for a year or two. LB is easy, Rose has went from strength to strength, while Shaw has been constantly injured and underwhelming in an attacking sense when played in some games. Blind and Darmian are not LB's.
Wanyama has been good for Spurs, much better than I expected but he isn't a great passer of the ball while Herrera is much more positive, it depends what you prefer really. Similar in terms of ability. Carrick is better than both.
Dembele is one of my favourite midfielders, but Pogba is not far behind him currently and is more productive and there's no doubt he will overtake him by the end of the season. I'd have Mata over Eriksen, but it's a close one. Ibra over Kane, but Kane has age on his side and will develop further but his overall game isn't quite there yet so he needs to work on that.
Hard to compare someone to Alli, he's obviously a brilliant talent and is only going to get better. Hard to really rate Mkhi so far, he's been in and out the side due to injuries but on paper, he's probably the best so I'll leave him out in terms of attacking mids/wingers. Alli, Martial, Martial, Mata, Eriksen, Rashford, Son, Sissoko, Lamela and Lingard in that order.
Overall:
De Gea
Walker Alderweirld Vertonghen Rose
Carrick Dembele Pogba
Martial Alli
Ibra
Not Martial's or Alli's best positions but it could potentially work, that would be a hell of a team.