One thing I will say about side by side tests. I've recently had two of the plastic coated traps side by side within 10-20 feet of each other in two different small ponds (4 traps total). I can have 30-50 minnows in one trap and the next trap might have 2-20. Next time I check it might be reversed. No explanation, just my experience. The minnows ain't talkin.
Same experience here...same trap, same size, same coating, same food, 5 feet apart. One time the left one will be twice as full as the right, then next time vice versa. No idea as to the cause.