When the Wade Barrett-led Nexus stable attacked John Cena, CM Punk and various other WWE personnel on an episode of RAW in the summer of 2010, the WWE Universe was turned on its head. The angle eventually went south due to bad booking, but the WWE has an opportunity to rectify the situation with its latest NXT-related angle.
At Survivor Series, Ryback was about to capture the WWE Championship in a Triple Threat match against Punk and Cena, but before he could cover Cena, NXT Wrestling stars Seth Rollins, Dean Ambrose and Roman Reigns attacked him. They eventually powerbombed him through a table, allowing Punk to cover Cena and pick up the victory.
Just like the original Nexus takeover, the invasion of the "NXT Three" came as a complete shock to viewers, but it universally has people talking about all the possibilities. Nexus seemed destined for greatness initially as it feuded with all of the top stars in WWE, but things eventually fell apart because the group was beaten by Team WWE at SummerSlam.
After that, Barrett was still relevant, but it was essentially him and a bunch of jobbers of little importance. Once the angle between Barrett and Cena came to an end, so did Nexus' relevance. Punk eventually took over control of the group, and it died a slow death after having so much promise upon its debut.
The creative team can't allow something similar to happen with Rollins, Ambrose and Reigns. All three men are generally considered to be blue-chip prospects with bright futures in the WWE, especially Rollins and Ambrose. Allowing them to go by the wayside would be detrimental to their development, just as it was for those involved in Nexus.
Once Daniel Bryan was released by WWE following the initial Nexus invasion, Nexus was put in a tough spot, because Barrett was really the only top-tier talent left. Guys like David Otunga, Heath Slater, Justin Gabriel and Skip Sheffield (as Ryback) have found moderate success since, but most of them are at the midcard level.
The current "NXT Three" needs to remain in its current state in order to thrive moving forward. That means no subtractions or additions that could potentially ruin things. Nexus got into trouble when guys were lost due to injury or other reasons and replaced with uninspiring choices. Rollins, Ambrose and Reigns can't afford that same fate.
Making a group or stable too big has proven to be disastrous in the past, with the nWo as a prime example in WCW. Adding more wrestlers to what we already saw at Survivor Series would be senseless, and it would simply take the emphasis away from the guys who should be getting pushed.
Also, it wouldn't be wise to feed Rollins, Ambrose and Reigns to Ryback. I realize that they're likely to feud with him, but rather than making Ryback run through them with ease, they need to be given some wins and be built up in order to look credible. Wins were few and far between for Nexus, and that resulted in only Barrett seeming like a big deal.
Rollins, Ambrose and Reigns need to be on an equal level rather than having one of them rise above the rest, though. All of them have immense potential, and it wouldn't be fair if two were overshadowed by the other. They simply need to be given every opportunity to succeed in the ring as well as in terms of getting over with the crowd.
Putting them with Paul Heyman would also eliminate a lot of potential pitfalls. Nexus didn't have an experienced guy leading the way, so they all had to figure things out for themselves. That may be the case for the "NXT Three" if Heyman denies involvement initially, but ultimately I have to believe that he will take credit for them and create a formidable stable.
This new conglomerate of NXT stars will inevitably draw comparisons to Nexus, but the WWE needs to do everything it can to avoid making the same mistakes. It isn't easy to instantly make the fans care about new superstars, so it is contingent upon the writers to keep the momentum going by keeping the group small, giving them important wins and putting Heyman in charge.