I can't speak for using a tom, because I've never hunted with one.
If hunting solo, I normally use a 2 hens and a jake. A big tom will see a jake with two ladies and know that he can ruffle some tailfeathers! A large flock can intimidate a shy bird, just like that strutting tom. But, a party could attract a dominate tom too. There is probably someone more knowledgeable that would say that during different times of the season you should set up differently.
2-3 is the general rule as to what I've done, with the exception of hunting a corner with a buddy (so we had more decoys). We put out two sets (2-3 birds, so 6 total) on either side of the blind, so that if the turkeys came from one side or the other, they'd see decoys either way. Hoyt and I did the same thing last year along a path.
Here was an unsuccessful stand in a hay field on a windy day when they were moving around quite a bit. I have a jake/hen set of those exact foam decoys and they blow around quite a bit. I have an old bitch hen that's solid plastic (don't make 'em like that anymore) and she doesn't move at all!
(PS - those decoys look familiar!)