Sometimes more is more. When a mature gobbler won’t come in to one or two decoys, show him a whole flock.
Specifically, show him a jake decoy throwing a party attended by three or four hens. In many cases, even the most cautious gobbler won’t stand for this. Set up along a field edge, placing the dekes in the open, well within gun range, and preferably on a knoll where they’ll be highly visible.
Put out two or three feeding hens and one with an upright head. Then place the jake closest to you and looking to your left or right. When jealousy gets the better of your tom and he comes in to break up the soiree, he’ll want to have a face-off with the fake jake.
This will put him in perfect position for you to take him out, before he realizes that he’s picking a fight with a hollow piece of brown plastic.