Yeah of course. WWE has huge amounts of talent and few stars, plenty of people in the company could do great elsewhere where Vince McMahon isnt deciding if they're what he wants from a star - height, moviestar looks, family ties to a former star, etc
Some make it without those things. Probably not without having to prove some people in the office wrong with huge crowd reactions or merch sales. For example AJ wasnt going to be a big deal in WWE, he had to prove them wrong. Daniel Bryan they've done everything possible to make him just a very good wrestler when he should have been the biggest babyface in the industry coming back from his retirement. Elsewhere they'd be rated purely based on what they can do in the ring and how over they can get with the audience. So most likely they'd be more successful in another company, but obviously a smaller company since WWE is by far the biggest