Just got done watching this Ross Pearson interview where he talks about why he thinks G Sot is behind the times because he trains each discipline seperately such as Monday Boxing Tuesday Wresting Wednesday BJJ etc and that he doesnt train enough MMA, particularly the transitioning between the arts.
Personally I train the arts seperately because I think that each art is way more developed than 'MMA' when you do it all together. This is how GSP trains (sure there is more but he's the famous one).
What do you think? To clarify of course you need to spar MMA and practice your transitioning, gnp, overall tactics etc but I think its more beneficil training arts separately.