When Rex and Peter find themselves in "the big shootout", stuck in a canyon below 20 ornery gunmen, Rex announces "I made a mistake. We can't beat this many men. Usually about 40% chicken out." If 40% of the 20 gunmen had chickened out, that would leave 12 of them — and Rex had two revolvers containing 6 bullets each.
All Western Towns Have The Railroad Coming Through...And each town is apparently the domain of a different Railroad Baron, who joins forces with the local Cattle Baron, gets defeated by Rex, and does not pass on any warning whatsoever to the other Railroad Barons.