That's why I said it's not perfect. But if the last week has taught us anything, it's a risk when you play Coquelin in there, who can't control possession in a high press to save his life. Having said that, Xhaka and even our best CM by far Cazorla, have badly struggled with the high press in the past too.
We can't quite replicate Kante-Matic because we don't have a complete mobile midfielder than can press, protect, defend, retain possession and create, like Kante (to be fair many teams are missing this). So a possession dominating midfield is all we can really muster up, otherwise we're starting Coquelin or Elneny who are unlikely to be precise enough to service the wing backs and forwards in possession.
It's preferable that we start players who are good enough to keep possession and contribute to good build ups when we do have the ball, rather than having a combination including the likes of Coquelin and Elneny.
I suppose in many games, you could go with Coquelin or Elneny in there and it would work out fine. The key difference with a 3-4-3 is that you have one extra defender, as opposed to a 4-3-3, is that you have the extra CB. That might afford us more leeway with playing less defensive midfielders.
Luckily for us, we have three decent ball-playing CB's in the squad. As well as quick and fit full backs to support on defensive duties.