Tactic Help

Hi, m using Man Utd & hv bought in a few players which are Alexis Sanchez, Lorenzo Isgaine (Napoli), Pogba & Gundogen. Sold Valencia, Young, Nani, Lindergaard, Butner, Cleverly & a few more going out...

Plan to play with 4-1-3-2 with both Rooney & RVP up top & Mata as the no.10 role...what's the best role for each player as well as the team instructions? I currently hv instructions set to a attacking/possession base style...

Rooney-Complete Forward
RVP-Complete Forward
Mata-Att Mid
Sanchez-IF left
Lorenzo-IF right
Carrick-Engrache dm
Rafael-FB
Evra-FB
Rio & Vidic-CD
DDG-GK

Should I change the formation? My AM says the midfiled is constantly overrun by the opp...should I play with just 1 striker?

Hope for some advice. Thks!!