[bluGill]

Is a mono repo the answer, or is the real problem you just have a bad repo split.

I can't answer that question, and there are reasons to go monorepo anyway. However if your problem is a bad polyrepo split going to monorepo is the obvious answer, but it isn't the only answer. Monorepo and polyrepo each have very significant problems (see the article for monorepo problems) that are unique to that setup. You have to choose what set of problems to live with and mitigate them as best you can.