It's a little confusing to me. Personally, I would just have a single line. People are less interested in which account posted something and more interested that an account post something. That's my thinking, anyway, but maybe for witness accounts managed by multiple people, what you're doing makes more sense.

For me, I'd view it like so:

or just something to group them together more easily instead of spreading them out as separate witnesses (when they are really the same witness)