I don’t believe workers are this expendable. Something is sure to go wrong at some point and there won’t be a worker with the correct knowledge to fix it. This can happen anywhere within the company. It can be an infrastructure problem (e.g. database failure), a software problem (i.e. a bug that could be fixed in minutes lingers for months), administrative problem, a payroll problem (and you’ll loose even more workers because payroll is flaky), PR problem, legal issue, etc.

With only 20% of your workers, there is no way these problems will be addressed with equal ease.