I followed the JST Theory for 2 atmas and here is the results

As of posting it is 5:48 in JST

Got atma of Goat ( 4-5 ) in 4:31 pm JST in the first fate
Got atma of Bull ( 5-6 ) in 5:42 pm JST ( lost count of fate but started farming since 5:10 pm JST )

So it is either pure luck coincidence or the theory is true in a sense that at least it did increase your bloody chance by a bit since i farmed in other zone before knowing about the atma theory for 2, 3 hours + and don't get one.