Experienced people and stupid mistakes
There are many, but a few of the main ones:
1) Call goes out to check on horses that mysteriously appear (could it be an ambush???), is shot, then his horse is shot, then instead of using the horse for cover and/or playing dead, he gets up and is shot again. Stupid & stupider.
2) Pea lets the railroad dude go and instead of using him as bait to take out Garza, he does... nothing. Railroad dude is wasted by Garza. Stupid.
3) In the boots for freedom trade, Pea shoots at Garza while on the run (instead of firing from cover in the far more accurate prone position) with a rifle and misses, is shot twice by Garza with a pistol at the same range, and then hits Garza at about the same range with a shotgun! In the words of Stallone in Cobra: "You're a lousy shot. I don't like lousy shots."
Then there was Mrs. Garza, who brought a gun to a knife fight... and lost. Stupid.
Raylan Givens: I told him he's got 24 hours to get out of town or I'm gonna kill him.