It’s hard to find ex-founders who are not good hires - especially for startups because they are self-starters.
And that’s what you need very early in your team formation. It is even better if they are deeply skilled in specific areas other than being generalists and are great communicators and collaborators. What happens when you hire a “bad” ex-founders? Many exist and they bring so much baggage enough to ruin not only a part of your business but even your team dynamics.
We can list 1000 character-company fit issues on why not to make a hire. On the other hand, what you’re looking for in an ex-founder can be boiled down to ownership and resourcefulness.
I have made hires that took so long and so much resources, and then on week 2 or so I’d discover it was in fact a bad decision. The worst decision here is actually inaction to let go or thinking time will make things better - rarely ever gets better.
If you made a sharp decision - you can slim fit your true expense to the cost of learning who not to hire.