Cristiano Ronaldo 31 year 55 games 4465 minutes 57 goals 16 ass
Robert Lewandowski 27 year 54 games 3856 minutes 42 goals 3 ass
Harry Kane 22 year 57 games 3838 minutes 33 goals 2 ass
Zlatan Ibrahimovic 34 year 56 games 3703 minutes 52 goals 16 ass
Dimitri Payet 29 year 45 games 2780 minutes 16 goals 13 ass
Olivier Girioud 29 year 59 games 2986 minutes 29 goals 6 ass
Wayne Rooney 29 year 44 games 2972 minutes 13 goals 6 ass
Alexander Lacazette 25 year 43 games 3463 minutes 23 goals 3 ass
These stats speaks for themselves.
We can only guess but if Zlatan can be injury free and continue one more season in similar style I expect with above statistics in mind somewhere around 15-20 goals and maybe 5-10 ass if he playes 3000+ minutes in all competitions, probably more. Suggestions he should only score 6-7 goals aren't built on statistic relevance. A new transformed United, led by Mourinho, with addition of Zlatan, Mhkitaryan and maybe one more quality RW will defenetly score more then 50 goals a season. I think above numbers works in his favor to hit the net more then 6-7 times Twigg. Don't you think?