Fox, I would have to figure out my own problems first!
On the trailing shuck, i don't think anyone would claim to know what a GG imitates, but I always think of it as a midge cluster, From what I have read, there is some debate on whether or not midges actually cluster, but if they do it is probably a post-mating behavior. So, making a huge leap in logic, I would think that a midge emerger would be a better choice if you think the fish are taking midges and ignoring the GG. On the other hand, it couldn't hurt to try.