We have a problem with one of our chief engineers, but we cannot fire him (yet) due to professional qualifications he holds, and it take time to replace him.
This engineer was a hard worker years ago, and won several promotions, and became a "chief engineer" 2 years ago. We have a problem that he spends way too much time training people on his team (and seems to have increased this effort after being denied a larger pay raise with his promotion). His team delivers results, but he spends a fortune on getting his team books, certifications, online training course, and on and on. We feel this is causing so many team members to only stay with his team for 2 years at the most, and then quit to work with another company or a direct competitor of ours. Our company is basically paying to train people that work for our competitor. All people on his team leave extremely positive comments on him when they quit, so we don't think he is being rude or mean to them.
His boss is retiring next year, and we can likely fire him then, but there is concern this will cause all those working behind him to quit. We need him to see that he is setting a bad precedent by doing this, and his goals of overtraining are bad for the company, and need him to stop this now, rather than in a year from now, so we can limit the damage. What is a good way to help him see he is hurting his own career by putting too much resources into training subordinates? He is based out of a remote office of 50 engineers/secretaries, as part of a larger company. It would be very expensive to replace the office, but we are ready to if necessary.
Part of the problem is the employee is qualified to teach others directly so they can take certain certification programs just by studying directly under him.