Yep. Gus had clout across the entire southwest at that point.Uh....nah man.
The ep where Mike and Jesse retrieve the stolen dope from the meth heads ("Cornered", season 4, ep 6) Gus and Mike are discussing their next move. Mike offers to get a few goons and wipe out the cartel. Gus says "for now, we keep this war cold" and decides he wants to set a meeting and see if they're willing to negotiate.
So they had the man power, Gus just didn't give the green light. He only decided to poison them after the meeting, when Gaff told them the cartel isn't going to negotiate.
Fred.
Declan is proof of that.