Wow. I don't think there is a single correct hand in any of these preview images.
Now, I'm in no ways and expert at creating AI images, but I've found that adding a prompt about the hand/number of fingers and creating a few more evolving pictures with that added prompt often fixes the issue, or if not you can add a prompt changing the positioning of the arm, so the hand isn't visible any more, if possible for the image you want to create.
If nothing else helps, you can often just add a few corrections yourself, to make the hands seem at least a bit more correct.
This might not be a major issue for many, but your models look pretty fine and for me personally the hands are definitely a detracting factor.