The game does not work like that. You can't say because Pakistan got out early, English team would score the same total they did. Maybe Hafeez would've played another blinder like he did in that 3rd Test Match when he scored 150. Maybe Shafiq would've scored a double century. Misbah was one of the team's top run getters maybe he would've gone on to get a big one. Sarfaraz was also a demon back then on those wickets, maybe he would've wagged with the tail.
Pakistan team was a better team than that English team in those conditions. If the team faltered, chances are the English team would score lower than the runs our team scored. That performance was the only decent performance by that team that entire series.
To rate Malik's double century as a better and more important knock in home conditions, compared to Fawad's is a travesty. Even statisticians and experts who know their cricket state that this knock requires tremendous focus and concentration. Its also the most balls faced by a batsman par Javed Miandad in foreign conditions. To summarize, Pakistan would've more likely than not done better than England in those conditions. And like the other two matches and the series before this, England's track record states that they would've underperformed regardless of Malik's inconsequential knock would/would not have done. (As the other games proved afterwards) When Malik didn't perform it didn't hamper the teams chances. Which is why he was an extra in that whole series and rightfully retired.
The guy was hopping around to English bowlers in flat conditions like those. Malik doesn't have the caliber to even face 1/4th of the balls Fawad has faced, let alone get a century. There is no chance that innings tops Fawad who is facing one of the best bowling attacks in the world currently with 800 wickets between them. Sorry!