Not too sure about MMA but in boxing I do an all round training routine by that I mean I try to train all major areas to be strong in all the movemetns of boxing where you use many many muscles in your body - quads, calves, abs, lower back, upper back, chest, traps, neck, arms, shoulders etc so I predict that in MMA you perform more variety of movements especially when grappling so i would train everywhere if I were you.
Please avoid Matt Furey. There are far better sources for advice out there, and many are much more reasonable in terms of price. I'm currently training an MMA fighter, and we only do one specific strength workout per week at the moment. What training you undertake is dependent on many factors such as your current work capacity, what your current activity level is, what your aims are and what time you have available to train. One thing that my current MMA student has found extremely beneficial is sandbag training, so this might be an area in which you should look in to.
you should do like a million shrugs so you get huge trapz. They will pop out of your affliction shirt