I believe you'll find that
as a general rule the 'proper' order is 1). Kohaku, 2). Sanke and 3). Showa based on their evolved size, conformation, pattern, color, skin, scale and finish.
No 'preference' is given at shows; it's all about the fish on the day.
Like Bern says, if you're placing a 'blind bet' then this would be 'the line.' Don