Agreement Term

Hi there,

I'm doing a business Law subject and I have the below question and hope somebody can help me:

There is a clause in the sample M&A contract, “except to replace employees on substantially the same terms, it is prohibited to employ....persons where the total staff costs of the company would be increased in aggregate by more than 8% p.a. from the total annual staff costs or single remenration after the recent salary review......."

What "except to replace employees on substantially the same terms" really means and how this clause really works?

Tks in advance

P