If I understand your situation correctly (you qualify for spousal benefits, but not earned wage benefits), you cannot receive benefits if he is not, so your filing would trigger both.

Depending on his age and how long he expects to live, he may be projecting this is less total benefits than if he delays it a few years so there's a potential case that what he's telling you is true, but he's not explaining it well.

Alternatively there are weird edge cases with tax cliffs that are hypothetically possible.

With that said, this is your decision and I am not going to presume to tell you what you should do, but i hope you find this information useful in some way.