McCarthy shouldn't be used anywhere but defensive mid. If you want to control games and consistently win games against poor opposition then you need midfielders who can manipulate the ball and create chances for the wide players and strikers. In recent times only Pienaar Arteta Osman and Gibson have been able to do this.
Barry McCarthy worked ok in the first season because Martinez had Osman and Pienaar doing the creativity ahead of them. Fine if you want to play that way but as soon as you lose your creative wide men you're screwed (as seen this season).
Besic and Cleverley are the same type of players. They can do a job putting tackles in and retaining the ball but they will not play penetrating passes to set up goal scoring opportunities. How many goals did Barry Besic McCarthy or Barkley get last season? They're not good enough! Gibson and Osman would do a better job as the deep lying two. We used to share goals around the midfield with Arteta Osman and Cahill chipping in with a good number season on season. Now we're an injury to Lukaku and Stones away from a relegation battle. We have a midfield that doesn't score, barely makes an assist, and doesn't protect the defence (based on last season's defensive record), yet people are coming out saying Barry and McCarthy are vital and undroppable. Can someone please tell me what the hell they're doing for us which is so good because u really cannot see it. All this season has proven is our over reliance on two 35 year old playmakers and that Maryinez has no idea how to play without them. It doesn't matter how many blades of grass NcCarthy covers if he's only going to pass it backwards once he gets it.