Julian
That is not correct. Without a CPL it is not legal to be paid for flying under JARs. Youa re thinking of the old CAA system. Since a PPL needs, in effect, as many hours to start a flight instructor rating as a CPL people no longer take FI(R) to hour build.
Also the groundschool may only take 6 months as mine did, not nwecessarily 12. I did not fly for that time, and went straight into the CPL without suffering for it. I did have quite a few more hours than most at that stage, but some hour building before and just a few hours after the groundschool is perfectly adequate. However I do agree that doing some hour building during groundschool (not too much, the course is very tough) can be a good idea.
Send Clowns
BCFT Groundschool Instructor