conditionality and Sanctions PC UC

couple where on partner is over PC age with the younger partner claiming JSA
No conditionalality for person in receipt of PC
Full conditionality for person in receipt of JSA - so whats the point of saying partner above PC age is not subject to any conditionality but partner can be sanctioned ?????

Where is the sanction comming from:
If partner of PCqa State Pension is more than JSA couple amount. - All thats left is Housing costs - are housing costs ring fenced, otherwise a couple of sanctions later and youre both homeless.