Re: Jo tsuki
In our style we practice several different variations on the Jo-Tsuki, each appropriate for a slightly different scenario. While writing this post I keep coming up with additional variations, some adapted for special situations, so I decided to forgo a number (having gone past 5 already).
Striking an head with a non-horizontal Jo can actually be advantageous in certain situations, yet less efficient in other situations.
The hand positions can be altered, as one advances. This again has both pros and cons depending on situation.
I guess if you were to check the entire koryu, you would have found out there are many move ways to correctly perform Chuki, then one could learn in a decade.