Since they operate on long runways only it is not a problem.
And what happens when said pilot looks in the manual, sees that the landing/takeoff distance required is x including safety margins, and runway available is only 150m more than the POH says, then he/she (as trained) attempts the approach at 1.5Vs....
That's a disaster waiting to happen!! Not a safety margin for the clubs!
If they are not capable of flying within normal limits, should they be allowed to solo in their planes until they have shown that they can fly accurately?
I'd say teach the POH, show at altitude WHY you follow the POH, then hopefully your students can learn to land!!