Emery started both Alexandre Lacazette and Pierre-Emerick Aubameyang against Cardiff on Sunday.
The forward duo both scored in the 3-2 win in south Wales to give Emery his first points away from home since becoming Arsenal head coach.
It was the first time the Spaniard had picked his two star strikers in a starting XI for the first time in a competitive game.
Merson believes Arsenal’s defence is their weakness and they need to outscore their opposition to win games.
And the pundit says playing both Lacazette and Aubameyang is the way forward.
“I think they’ve got to play that way,” Merson said on Sky Sports News.
“I don’t think they’re good enough at the back to only play one up front because they’re going to have to score goals to win football matches.
“You look at Cardiff this season, they’ve been pretty negative in the games they’ve played.
“Then they go and play Arsenal and they have a go, so that tells you everything, that Arsenal are not as strong at the back as other teams or certain teams.
“I wanted them to to play up front, I think if you play them two up front you’re going to score goals.
“If you score goals, you’ve got every chance of winning football matches.
“They’ve got a few good fixtures coming up at the moment.
“I think they should play the two and get the points on the board.
“Like I said I think they need to score goals.
“If they don’t score goals, they’re not going to win football matches.”
After the international break Arsenal visit Newcastle on Saturday September 15.