A lot to dive into, at a quick temporary take I think you have to consider locus of control for the judgement construct. A person could experience impostor syndrome strictly with interactions of their own beliefs about their qualities/quality of their work/effort contrasted with their beliefs about the same thing of others.

Once it becomes beliefs about others' beliefs then the intersection may be identical.

It's an interesting chain as many qualities play off of it including unconscious self-sabotage. Shall return.