Aerodrome RFF crew have to complete Hot Fire training on an aircraft rig every 3 months something that Civil Fire Fighters don't do.
However, I believe that under JAR Ops the responsibilty for correct RFF Category at Aerodromes lies with the Aircraft Operators. Now an Aircraft Operator can accept a lower category RFF if other measures have been put in place.
An example is Debonair. They wanted to set-up a schedule to Pontoise which is published as CAT5 but the BA146-XXX that they wanted to use was a CAT6 aircraft requiring one more firefighter. Debonair were able to negotiate that everytime their flights operated in and out of Pontoise that Jean-Claude from the local fire station would jump into his Citroen and go to the airport to provide the extra man.