Ok, so they use there actions together, except when in cc, then they both get to use their actions to attack? Now I am looking at a Bushido Dragon rider. These guy's are pretty confusing. You can only use the Naginata during a charge. You can also only use the headbud during a charge. But why would you ever use the headbud instead of the naginata when it is less likely to hit and does less damage? So in the case of the bushido dragonriders, i am assuming that if you are three inches away from an opponet when you begin your turn then you can get 6 attacks off. On the charge you get the headbud from the dragon rider and your naginata (but it precludes secondary attack, so no seconday attack with the katana on the charge), then your next two actions you use with the katana and secondary attack.
AS for the cossacks, they generally make sense; you would want to use the beast in cc and the dragonrider in RC.
I think putting all the information in one statline would have made things simpler. then just a special rule note about the mount attacking.
Note: The first sentence of this is what i thought was implied by a previous post but by the end of it I disagreed with it.