Yes, at the pro level genetic shape and structure are of paramount importance--if you want to go all the way. Just being huge, balanced, and conditioned may get you some wins at lower-level pro shows, but at his height, even with all that muscle, placing in the top spots at the Olympia is not going to happen. We see a similar situation with Big Ramy. While Ramy is certainly bigger and better than Nick, the point here is that Ramy consistently gets beaten by guys with much less overall muscle tissue, but who have greatly superior shape, structure and detail. Dexter Jackson comes to mind.
If Nick stays the course and continues to progress, I see him slowly climbing up in the placings, but not ascending beyond mid-level placings at the Arnold Classic. He could possibly move into the upper spots at the ASC, but I believe that would require a weaker line-up. Top 6 at the Olympia? Nope. I suppose anything is possible, but it's highly unlikely. No matter how big he gets, he isn't going to be able to change his shape, height and overall structure. The only cards he really has to play are size and potentially conditioning, but there are plenty of guys who come in with equal conditioning and some with better conditioning. So, unless he comes in diced to the bone, conditioning isn't really going to win him extra points with the judges--not enough to jump past guys who are equally conditioned with vastly superior shape and structure.
Now, if Nick had that same body on a 5'11 frame, he would be a bigger threat--similar to Big Ramy--but it's hard to rely on size alone to win top level pro shows when you're 5'8 (that's his height, correct?). While 5'8 isn't really considered short by bodybuilding standards, it's not ideal either. If we look at history, the most dominant and highly praised bodybuilders fell in the 5'10 to 6'0 range. This includes Mr. Olympia winners (Haney, Yates, Coleman) and non-Mr. Olympia winners (Wheeler, Levrone, Dillet, etc.) That height range typically enables a genetically gifted bodybuilder to display a more dominating stage presence, while maintaining the structural proportions necessary to be among the best. Once a bodybuilder gets beyond the 6 foot mark, most of them suffer from some type of structural issues....and the taller they get, the worse the problem becomes. We've all seen 6'5 bodybuilders out there, but they never go very far because they typically have glaring structural issues, while also acing the ability to fully fill out that frame.
The same thing happens (from a structural standpoint) to shorter bodybuilders, as well. Once a bodybuilder falls below the 5'10 mark, he starts to lose that towering, dominant stage presence...and structural problem become more apparent (in most cases). I would say that 5'8 is kind of the cut-off point for maintaining a good structure. We see plenty of guys in the 5'8-5'9 range with great structures (proportionately speaking), but once they fall below that, issues begin to creep up...and the shorter the bodybuilder gets, the worse it gets.
While Nick is a great bodybuilder and should be praised for what he was able to achieve in such a short period of time, he is going to run into problems against the top guys. The top Olympia and ASC guys are not only big, but typically display fantastic shape and structure relative to the lower and mid tier pros. Even better, they often do this while displaying a large degree of muscular detail, as well. Nick is going to struggle against these guys at the top levels. If he attempts to rely on muscle size and continues pushing the envelope further and further, not only will it do comparatively little for his placings, but he will eventually begin to ruin his physique...and his health.
At this point, if I was Nick, I would stop focusing on pure size procurement and instead channel all my efforts towards working on improving key areas of individual muscles, while keeping my waist under control and further improving my conditioning. If Nick wants to ascend as high as he can, he needs to build the best physique he is capable of, not the biggest....and he needs to d this while keeping a keen eye on his waist. It will be critical for Nick to avoid blowing out his midsection as he gets older. Right now, at 23 years old, his waist is the smallest it will ever be. It WILL grow as he gets older, so he needs to take steps to prevent that from happening as much as possible...BEFORE it begins to detract from his physique. If Nick is able to keep his waist under control while strategically adding 8-10 pounds of muscle in key areas...while further honing his conditioning, he will do quite well. On the other hand, if he continues prioritizing size, he will never realize his full competitive potential.