How do you describe the issues in project organization structure with that of permanent client organization structure? explain: client organization

I don't see any relationship between project organization structure and the client's organization structure.

The client organization structure desribes the classification of the client's staff into departments and functions within his/her company.

I believe there is no relation in any way between project organization structure and client organization structure.

For example: if you are working on construction project and your client is company AAA, then by CONTRACT only they can obligate you to have1 full time project manager,1 full time construction manager, and so on.

Then you can propose any structure you want for your project and without looking at client organization structure because your client will never share his structure with you.