P&S process - leaseback

Trying to assess if my spouse and I are being unreasonable - we are having a bumpy P&S process....

We are in a very competitive HCOL market. As part of our offer, our realtor encouraged us to offer a free 60d leaseback since the sellers are actively looking for a new house.

We were (of course) apprehensive about this part of the offer, but our realtor assured us that this has become fairly standard, and that we would be able to agree to Use & Occupancy terms to offer us protection & peace of mind

We won the offer, inspection went great.

Fast forward to P&S, we are getting pressure from both our attorney and realtor and the Sellers attorney to sign the P&S (which states that the sellers can live in the house 60d post close without any other terms) without agreeing to Use & Occupancy terms. They just want the milestone hit This seems to put us at a disadvantage and we are at a standstill until we can get the Use & Occupancy terms attached to the P&S .

Are we being unreasonable??