I've been maining SAM since SB dropped and I'm pretty up-to-date with current SAM techniques, and I have never seen that opener that you're using. The base priority for buffs is generally Shifu > Jinpu > Yukikaze (slashing debuff). But I'm going to leave this here:
https://docs.google.com/document/d/1...t?usp=drivesdk

This is a pretty decent guide for SAM usage and rotations. The math goes over my head, but the general knowledge of Higanbana timings and Hagakure usages really helped me improve. SAM openers are generally dictated by your currennt skill speed, and that guide goes into detail about it. Hope that helps! Have fun!