Sumo can also be done with a narrow stance. It is worth trying it out. I didn't like the wide stance. I was introduced to the sumo narrow stance in the SFL user course and intend to adopt it. This is probably because I can deep squat with my elbows easily inside the knees in my goblet squat. It felt like carryover. Interestingly, in the SFL course, it is recommended that everyone start with sumo after competency in the goblet squat. It is recommended to do both as a beginner-intermediate at least. Sticking to the overhand grip as long as possible was recommended and if pulling a mixed grip then switch up the grip to prevent imbalances. My own view is to avoid a mixed grip except necessary when testing a PR. It seems to ask for developing imbalances and poor form.