Simplifying definitions, coaches know the right questions to help you find the right answers, while mentors assist you in opening doors which have been opened before and consultants solve problems on your behalf.
Companies hire business coaches, mentors and consultants when their results are below their expectations, firms want to boost their businesses or there are issues in healthy companies which need to be addressed. Both coaching and mentoring should give a client new energy and valid alternatives to make necessary changes happen.
I would risk a thesis that every leader or manager (even very successful and experienced) would benefit from having a very good coach, mentor or consultant. It is because they can help you see issues from an external perspective. A manager who claims to know and see everything around him/her can hardly be called a leader.
There are plenty of coaches, mentors and consultants on the market. Like in other professions, not too many of them are really good. Few are very good at combining coaching techniques, vast business experience and ability to perform consulting to their clients at the same time. They can be called:
A coach/mentor/consultant in one
The selection of a very good business coach/mentor/consultant is a quite complex task. Many coaches with psychological background have a very limited business experience. Few serious CEO would ever listen to questions asked by a 27 year old coach, even with a valid coaching school certificate.
Too many experienced managers do not know coaching tools, not to mention their underdeveloped soft skills.
Top consulting companies are not affordable to a majority of SMEs and their value for money proposal is often questionable by many managers.
I see here two conclusions that can help you in your current situation.