I have been asked often what do I think about having different coaches for each of the major disciplines that make up MMA.  People often seem really excited about having a Boxing Coach, Jiu-Jitsu Coach, and/or a Wrestling coach.  MMA in the U.S. is a relatively new sport.  The first ever UFC was held in 1993 but it was still pretty much just individual disciplines vs. each other.  It wasn't until about 1996 when you really started to see the beginning of fighters blending arts to fill the voids in their respective disciplines.  Today MMA is the fasting growing sport in the U.S. and people/gyms are desperate to "Jump on the bandwagon."   Martial Artists that have dedicated their lives to just one discipline are realizing (thanks to the UFC) that they have many "holes" in their game.  I have seen so many fighters at all levels fight with a compartmentalized mentality.  How many times have you seen a fighter  punching from inside someone's guard with no thought to protecting their arms against submissions?  They are solely in "striker" mode.  How many times have you seen a fighter attempting to apply a submission while not considering the possibility of defending strikes?  In my opinion that is a result of having different coaches for each discipline.
  A boxing coach may be very skilled at his craft, but he has no concept of someone kicking his legs, throwing elbows/knees or shooting in for a takedown.  In his sport when a clinch occurs, the referee steps in and separates the fighters.  The coach has often learned his skills in a boxing ring and not a cage.  A boxer only has to deal with punches above the waist thrown at very specific angles.  A pure boxing coach that simply knows that MMA is a different sport will not override the tens of thousands of repetitions he has done when it comes to stance, punches, defense, and footwork.   
  A Jiu-Jitsu coach while very skilled at their craft, often train in the gi which is not used in MMA.  The MMA gloves that are worn makes it more difficult to pummel as well as slip in chokes.  The Jiu-Jitsu practitioner is not accustomed to being struck while on the ground.  Some of the best Jiu-Jitsu practitioners find it very hard to submit someone who is very good at ground and pound.  Their skill level seems to drop with every punch that lands.
  Wrestling coaches have their own set of problems when it comes to MMA.  Their shots often leave them vulnerable to knee strikes and they are not accustomed to defending punches or knees while wrestling.  They are also not used to defending against submissions and are not use to fighting off of their backs.  They also have created muscle memory for turning their backs to their opponent because they don't want to be pinned in their sport.

The truth is that there are not a lot of qualified MMA coaches (Notice I said MMA).  When most of today's coaches were training in martial arts in the 1980's and 1990's it was unheard of to train in more than one discipline.  It was considered disrespectful to train in any other discipline other than the one you were currently training in.  After all it was customary to dedicate your life to one discipline.  I was one of the few in my day that cross-trained in Martial Arts.  I realized early that there was no "art" that had all  the answers.  I had a successful kickboxing career as well as earned black belt levels in Jiu-Jitsu as well as 2 other disciplines.  I was ridiculed by my peers for doing this.  I was considered the "black sheep" of the martial arts community when I opened my doors in 1995 since I wasn't teaching a pure discipline.  Today that mentality has certainly changed with the popularity of MMA. Turns out that I was way ahead of my time.  This gave me a huge advantage over my peers when it came to training fighters for MMA.  That explains why there are so few experienced true MMA instructors. 
  I am not suggesting that these individual coaches cannot help you with your MMA game. In fact, if you are already accomplished in a discipline, then a specialized coach for a discipline that you have not trained in, can be of great benefit. But the difference is that you already have a strong background and knowledge in one area from which to build. For instance if you have a black belt in Jiu-Jitsu, you will already have an ingrained grappler's mentality when you start training with a Muay-Thai instructor.  But if you are brand new to MMA,  if you have the opportunity, train with a coach that has earned black belt levels in grappling as well as striking arts and/or has high level accomplishments in boxing or wrestling. Seek out a coach/gym that has a thorough understanding of all aspects of MMA, rather than multiple coaches who each offer only one component of the sport. 
  I welcome intellegent respectful discussion.