Support staff at a newly acquired company

My hypothesis is that most newly acquired companies won't have in place the support team that the incoming CEO might need to stay on top of things.

The newcomer CEO needs to absorb the role of the previous owner(s), learn about the company and the industry far beyond the DD analyses, and push the whole organization beyond the current inertia.

Does anyone have experience on hiring support staff (administrative assistant, chief of staff, business analysts...) for the CEO office right after acquisition? After a while? what went well? what could have gone better if?