Preventing offer approvals where no positions left

Summary

Issue whereby a hiring manager can create an offer/send an offer for approval when the number of vacancies are already filled but the vacancy is not set to be hired/internal/external

Content

Hello,

We have an issue whereby our offer approves are spending time approving offers only to find that the vacancy has no positions available which means the offer cannot be extended to the candidate but is now in an approved state and requires the hiring manager to edit the vacancy and re-approve the vacancy with more positions. We were wondering if anyone else has come across this issue before, and if anyone has any advice on how this can be set up differently/resolved