The home side were in front after only 70 seconds at Emirates Stadium, when in-form Croatia striker Eduardo bagged a fifth goal in three appearances.
Togo frontman Emmanuel Adebayor latched on to a long ball from Gael Clichy to net a second from an almost impossible angle, which all but ended the game as a contest before the break against a tired West Ham side.
"Sides who play 4-5-1 here and mark us very tight, they push up very high. Therefore the defenders have to play on the half-way line and with the players we have, that enables us to go behind the central defenders," said the Frenchman.
"That gives us naturally a different option. We always have alternative options.
"We have worked on it, because we know Adebayor has so much pace and power and Eduardo is shrewd as well and a clinical finisher. It's a great option for us."
The Arsenal manager continued: "We had a great start and after that we controlled the game.
"West Ham were dangerous on set-pieces in the first half, but in the second half we were in control without ever pushing to score more goals.
"We didn't want to concede and West ham didn't really challenge us so we were quite comfortable."