Ohhhhhhhhh... goddamn, sorry about that. My misunderstanding. I should read more carefully.
When I play with my thumb I'm generally going for a more subtle tone that stays on the E string, but I use both my index and middle fingers in conjunction with my thumb if I won't be on the E long and am doing a ride that transverses to the other strings. It's easier than moving the hand. But there's a little difference in tone and control of how you hit the strings in either scenario.
I think you'd be well served to learn multiple ways of fingerpicking on the bass and not getting locked into a specific thing, because you'll have more options that way. Get comfortable with different methods and learn how each method affects your playing.
