Even though Liverpool would've still won, Emery should've started Lacazette and Torreira. You have to put your best XI in games like these
The floodgates would've opened sooner. Arsenal might've gotten a goal earlier, but Liverpool would've had 3 or 4 by halftime. Arsenal don't have the guns to go toe to toe, especially not at Anfield.
Emery had the right idea at the start. Flood the center and concede the wings to Liverpool's fullbacks. It means letting Liverpool cross over and over into the box, but that's better than letting Salah and Mane run riot in the middle of the park.
Where Emery fukked up was the halftime adjustment of pushing his fullbacks into Liverpool's half. Naturally 2 minutes into the 2nd half Luiz is forced into dealing with Salah 1v1 and hilarity ensues.