After about a week or two of playing ancestral, I think this variation is good and shouldn't be considered as bad. One of the problems is punishing moves when you have no stun arrow but the solution for really punishable moves like ex slide(Sub) is to use instant njp, 26% into stun arrow and mix-up. If not, I just do 343 bf4.
People say Kung Jin has no mix-ups cause they are fuzzy-able, I agree but this vid has shown another way to mix people up that is safe. I think its necessary for every ancestral player to learn ia dd2(for mixups and plus frames), ia db2 ( for zoning) and ia df2(basically for anti air reads and combos). If you do ia dd2, low enough it can't be punished and I consider it a mix-up. Also doing f2 dd2 is really good from f2's max range(can be armored tho), a lot of chars can't punish the dd2.
One of the problems of bojutsu is unsafe overhead(no big deal imo) but in ancestral you get both safe overhead and low mix-ups. One thing I found really good is using ex-arrow for pressure and breaking armor. With stun arrow, you can blow up wake-ups with ex arrows(from ia dd2 mb {leaves u at like +13 even if no wakeup comes out} or df2 mb). D4 ex df2 is also really good, especially with stun arrows.
Zoning with ia db2. From experience loading stun arrows full screen doesn't cause much threat cause your opponent might wait for you to waste it but against a character like mileena, you can react to her low sai with ia db2(stun arrow) and run in for your punish. Using fire arrow is really good - the damage and it does lots of chip(0.20 less than d2). Using the vampire arrows are also really good, stealing your opponents meter and frustrating them. Sometimes forces them to come to you and make mistakes.