Maybe, and there was no way Martinez would no how well Van Dijk would adapt. Its like bemoaning the fact we didn't sign Manolas all them years ago, who's to say he would've turned out like he is now and not another Shane Duffy. (ie. not a superstar nothing against Duffy).
I would argue Duffy has gone on to show that we were wrong to sell him
Him and Stones together as centre back pairing would have been exciting stuff in my opinion
Gana and Gomes have shown in midfield that a contrast of styles in a partnership can be a good thing