They all kill turkeys dead with the right load and good shot placement at a lethal range.
The advantage of the shorter barrelled shotguns involves both range of motion and concealability.
When you're hunkered down behind a blind (natural or manmade) or a tree, bush, briar patch, etc., you have a better likelihood of drawing a bead on a turkey's head if you can move your shotgun without rustling limbs or catching the eye of the turkey. To this end, some of the shorter barrels offer a bit of an advantage. Notice I say a bit. Plenty of turkey hunters out there use 26" or even 28" barrels and do just fine.
My turkey gun has a 23" barrel. Works for me.