If you look at the Arsenal game last Saturday I think the first team was more or less evenly divided between the two halves.
I think probably three of our starting back four played in the second half(Tarkowski, Keane and Mykolenko), as well as Gordon and Iwobi.
In the first half we had Doucoure,DCL... possibly Patterson and possible one of the centre back and maybe Gray or Dele.
It was used more as a training and fitness exercise by us than it was by Arsenal..... who do have a very talented squad anyway.
For me....WE have to find an attacking wide player to replace Richarlison and I assume it will be Cornet and/or MGW.
But, more importantly we need bodies in for centre midfield. We need a midfielder who can defend but also use the ball well to set up attacks and really as well we need a creative no. 10 which ironically we don't really have any of now.
While I do agree with you when it comes to how Everton played against Arsenal, I don't expect Everton to play the same way as you do.
Lampard had a pretty good first season with Chelsea, but they were never sound defensively. His second season they could not defend. Not at all. Tuchel came in and within weeks Chelsea had the best defence in Europe. With the same players. Of course Lampard studied what Chelsea did different under Tuchel. And he has all the insider info he needs from Joe Edwards that was Tuchel's assistant manager.
Lampard seemed to prefer 3CDs last season. He played with 3 at the back against Arsenal. As of now, we should not speculate in who's in Lampard's back four.
Also offensively against Arsenal Everton looked similar to Tuchel's Chelsea team. We didn't really play with wide forwards. Width were provided by wing-backs and the front players played so narrow that it seems mote accurate to say that we played with two number tens.
A 3421 formation should be a good fit for the current Everton squad. And with minor tweaks and changes in personell, it will also give tactical flexibility. Both between matches and during matches.
My main concern is where the goals are coming from next season. We should not expect more than 15 goals from a fit DCL. If Everton are great defensively we need 30 more goals from the rest of the team. Most likely we need mote than that. If we improve on set pieces, we can hope for 6-8 goals from our defenders. How the heck are we going to get +30 goals from the midfielders?
Gray, Iwobi and Gordon are players that will give you 4-6 goals a season. That is a concern. And probably why we are linked with players such as Cornet and Gibbs-White. That might not be the most flashy or exciting players, but are more of a goal threat.
Also a reason to try to do whatever we can do make Alli good. He is a proven goal scorer.
We can hope that Gordon can give us 10 goals a season and can outscore players like Cornet and Gibbs-White. But we should not expect it.
With five subs we could have a pool of players to play behind the striker. Expect a lot of running and pressing from them. Never need to play them more than 60 minutes per match.