Hi,
The catskill patterns were tied to specific dimensions (tail length, abdomen length, thorax length, and wing height). This was done (I believe) in order to maintain the "float line" of the fly - so that tail tip, hook bottom, and hackle tips touched the water simultaneously.
Yet, the tails of real insects are much longer and often tied as such. An example are the extended body flies, etc.
Often, I think we restrict the tail size because of the old Catskill reasons. I think most would think the tails on this rusty spinner are too long, but if you look at a photo of a real spinner, their tails are quite long.......
What do you think?
Thanks,
Byron