there could be a wealth of experience dumped on the market to train future pilots.
Good luck for anyone contemplating on doing this, the industry would certainly benefit from a few more experienced people getting into training.
While flying experience is a plus for an instructor it by no means guarantees that person to be an effective instructor. Good instructors are born - not made. An airline captain with upwards of 10,000 hours you would assume to be a "good" instructor when his students only know him as a sarcastic screaming skull. Few have not had the occasional misfortune to run into these types in airlines and general aviation.
A brand new Grade 3 with 300 hours may have no real life flying experience outside of his local training area. Having said that, depending on his personality he may turn out to have just the right temperament - quiet - not a shouter - and genuinely enjoy his work. Best of all he remembers that: “At the end of the day people won't remember what you said or did, they will remember how you made them feel.”
― Maya Angelou
It is a great pity this adage is never mentioned on instructor courses - RAAF, airline or general aviation