Former Arsenal defender Mikael Silvestre feels they're being rewarded for a positive summer market.
The Gunners are equal Premier League leaders after defeating Manchester City on Sunday.
Silvestre told bettingexpert.com: "The squad depth paid off, absolutely.
"They knew they had to thicken the squad after last season where they were a bit short towards the money time - March, April - that's where they started losing ground.
"We are early on but you can count on these players to be difference makers.
"When you're the opposition and you see these players [Martinelli, Havertz, Partey, Tomiyasu] coming in, you're like 'this is not going to get any easier' because the guys are great players and are fresh'."
He also said: "That's why they spent 100million on Rice. For these types of games.
"These types of performances, tight wins, can be the difference between winning and losing the title. That's why they were so disciplined."