Maybe but there's tons of guys doing that now and they do not have that skill set.
In order to be better than the crowd you have to be different from the crowd. What kind of training could one do to craft such a style
There's a lot of people training a lot of different things, but what kind of training are they getting?That's why I've never felt the whole "new breed" of MMA was as good as it was made out to be. In the old days, the guys came from pure styles so they might have had bigger holes, but in certain areas they were far superior. A few years ago most MMA gyms started catching on and some are now cross training at good gyms and going to the source directly, which is why we see some things improving (especially striking). Even within pure sports though, there are levels to training, so you have to know where to go .Anyway. point is, you'd need to go the to source, learn from the best at what they do, and then take from it what works best for you and blend it together in a way that best suits you and the ruleset you'll compete at. You'd need excellent coaching staff and trainers to be able to do that, and be extremely talented as well. Tayski had a good point with how the individual matters.
Basicly it would be; Learn the basics of punching, footwork, feints, rhythm, hips and positioning from highest quality pure boxing source you can. Learn the basics of knees, kicks, elbows, clinch and trips from the highest quality pure MT source you can. Learn the basics of the takedowns, takedown defense, wrestling drills, chain wrestling and control from the highest quality pure source of wrestling that you can. Learn the basics of throwing, push/pull, trips and takedowns from the highest quality pure source of Judo that you can. Learn the basics of the guard, sweeps, submissions, body manipulation and body positioning from the highest quality pure BJJ source you can. And so on (pick TKD, Karate, Catch Wrestling, Sambo, whichever). Take from those sources what fits you, your style, your mindset and blend them together in a way that let's you express yourself and be creative. That's the ultimate goal to me.
Realistiscly being very proficient at a few things or elements, while being decent enough to not get overwhelmed in the others is the way to go. Also some things naturally flow better into each other like wrestling/judo and boxing (fake takedown, use the uppercut. Slip jab to the outside, go for the single leg takedown. Fake the double, use the overhand. Use the overhand and/or handtraps into the clinch. So on).