Pigeon shooting
PETER THEOBALD says:
I must say that I have not seen the decoys you describe, though I do have a book on pigeon shooting where the author advises painting some of your decoys to resemble young woodies, so that the layout is more realistic.

I cannot imagine a pigeon looking at your pattern and thinking to itself  “I’m not joining that lot…there are no youngsters feeding with them” or, “I can’t see any crows feeding with those pigeons so there must be a human with a gun, hiding somewhere.”

The fact is, pigeons do not have the power to reason, reacting solely by instinct and habit.

If the visual impact of your pattern is to their liking, it matters not a jot if there are young birds amongst it or not.