My daughters show poultry in Michigan through 4-H.
Our best chicken for showmanship is Jane, an Old English Game Hen. We have bantam Cochins for showmanship too but they are about double the weight. I think we will purchase more OEG for showmanship, my 2nd daughter is almost 10 and her Cochin bantam is too big for her. It was perfect last year as a pullet.
We have an assortment of birds. Black Austorlorp, Buff Orpingtons, EE's (which cannot be shown, unless you have a mixed breed class), Ameraucana's, OEG bantam, and cochin bantam.
My oldest daughter, Rachel, (who is chicken crazy and 3rd year showing) won grand champion production hens with the black austrolorps, Best hen in the barn with one of the winning production hens, champion standard hen, champion standard pair, reserve champion bantam pair, reserve champion bantam.
2nd daughter, Emily, her first year showing animals, got reserve champion doves. She placed in mixed breed (1st year only can enter this class), and her cochin bantam.
Since the fair a wild animal got the male dove and took it out of the cage that had chicken wire. And got the leg of the female. So we are done showing doves for now.
Best advice I can give you is to have the kids talk to the judges after the show and see why he/she placed the birds as they did. This is very knowledgable for the kids. They can take that information and use it to their benefit during showmanship, pointing out the birds flaws for that breed standard.
Good luck and enjoy showing your poultry. We sure do!