His actual diagnosis will affect how much he ends up paying, as some of the cost may be met by the local council.
So, for example , if he needs personal care ( as most probably do) , help with washing, toileting , etc, this element should be paid by the council as they would if he needed this support at home; if he qualifies for Attendance Allowance at home, this is the equivalent,
If he has medical needs which require nursing, this element will often qualify for funding. So the headline care fee may be ‘discounted’ for these items.
Thereafter, bed and board will be paid out of his assets, which would include pension payments. He will have a weekly allowance ( currently £34.50) and a total savings allowance. Which I think is £23k (?) in Scotland.
Once he is below the limit , the council will pay , but do check that the home will keep him, in the same room, if he becomes council funded, before getting him settled, as it’s not unheard of for residents to have to move when funds run out, and this can be confusing for them.
DH went through the assessment process for MIL but she passed before she was settled. He found the care manager to be very helpful in walking him through it all.
He would have to sell her home as she had very few other assets, but that was expected.
Sorry, that was an essay, but in my very limited experience, a decent and realistic care needs assessment and OT review are key. It needs to reflect their bad days , not their best days IYSWIM.