Looking for advice - learning clawhammer

So I just started learning clamhammer about 2 weeks ago. Last night I finally implemented some left hand chords. I’m having a hard time getting a good “rake” when I play the first string. I’ve found that leading with my index finger on the “bum” feels most natural for me. Do people switch to their middle finger ever when playing the first string to get a better rake on strings 2 and 3 with their index. Obviously I need to practice more, but just want to make sure I’m getting a good foundation for my technique before I develop any bad habits. Also a lot of the videos talk about kind of striking like a drum instead of a guitar strum. I’m trying to do it, but I also play guitar. Am I on the right track from what anyone can see? Thanks in advance for any advice!

Ps I know my timing speeds up and slows down, and I mess up one of the changes at the end lol