lorddulaarsenal
That's effectively how we played last season anyway.
Given the players we've been linked to, I expect we'll still see 3 pure defenders and 1 fullback that moves into midfield. The difference is next season we'll have the option to set-up both ways - Kiwior and (a tucked in) Timber vs White and (a tucked in) Zinchenko. So, we'll be way less predictable and not as reliant on Zinchenko's fitness.
I think Caicedo was the first choice for that role, but having watched some videos of Timber, it looks to me like he can offer a lot of what Caicedo could from the tucked in RB role.