Defensive-wise, I can agree it is a different story playing with 2 or 3 CBs and requires different responsibilities for different spaces, but in possession, I think formations are barely just numbers and we should have a closer look at the principles of play and shape of the team while in possession to see the whole picture.
Here is Medina's passing map this season with what should be an average shape of Lens as a team in possession.
What we can see is that there are numerous similarities in the way they are positioned and how our usual shape was in most of our matches and I previously described that here. One difference that I forget to mention here is that when we have both Shaw at LB and Rasfhord at LW we can see a passage of play when Shaw maintains the width and Rashford attacks the half-space.
My point is that, despite roles being different, the positioning of players, the spaces they occupy, and the passing lanes are very much like ours so Medina should be ok with what is his strongest ability as a CB - progressing the ball further up the pitch.
When you already mentioned Shaw, the truth is that Shaw already showed that he can be a backup for Licha and we could be looking for someone to rotate with Varane instead. But if Lindelof can maintain his recent form and cover the RCB position, it will be a big positive for our performances with Medina in our squad that we could rest Licha and play Shaw at his natural LB position without having to field Maguire.
That alone makes him an attractive option as he shouldn't cost much and if we are looking for a rotation option for LCB position he could be the best bargain option in the market.