RE: Shorter ATA Bows?
I am also a staff shooter and I agree that you should stick with a longer a-a bow(37" to 40").Especially since you are new to the sport.I would also suggest a brace height over 7 1/2" with a moderate reflex or a deflex riser.A hoyt Protec would be a fine choice imo.This is my bow of choice for 3-d.
As far as the wingspand method of checking draw length.I have yet to see it be right for anyone I know.I myself am drawing about a 1 1/4" longer than that method if memory serves me right.I have been coached a little by a friend that has coached world champions and he says my draw length is good at 28 1/2" to 29" and I am 5' 9 1/2" tall(I do have long arms).I shoot much better at 28 1/2 so I am confident this is my draw with a loop.If you were checked with the bow in hand and were comfortable with the anchor,I would say the 29" is pretty close but can't say for sure because I wasn't there.