If they are QFIs then they will be military pilots and local powers of authorisation will define precisely the degree of supervision required.
There is NO SUCH THING as a civil 'QFI'. You are either a FI qualified to teach for a JAR-FCL licence or rating, an AFI under the old UK system but still qualified to teach for JAR-FCL having signed the 'declaration of knowledge' certificate - or a FI(R) having graduated from a course under the JAR-FCL system.
If you cannot be more precise with your terms, then I suggest that you take some time out to learn the correct meanings and definitions. For example, do you know the difference between the terms 're-validate', 'renew', 're-authorise' and 're-issue'? If not, then you should. Too often we hear from FIs (usually airline wannabes rather than career instructors) who haven't bothered to keep up with the changes under JAR-FCL. That shows a singular lack of professionalism; I hope that they don't treat their customers in the same gash manner.