I personally would like to see Zubamendi over Lavia, as I reckon he'd be perfect with what Poch wants to do.
If we analyse his 2016/2017 tactics, Poch usually has Dier drop in as a sweeper from midfield which allows the full backs to push up and Eriksen to drop in midfield from the wide area. Having Zubamendi will give us another anchor who's good in the transition and will make us defensively strong in midfield.
GK
Fofana Colwill
Zubamendi
Caicedo Enzo
James Chilwell
Nkunku Sterling
ST