Rude was a god talker but he couldnt wrestle, he was done after 94 -so essentially he would have just been a manager, he might have done well but I don't think it would have done much to rise his level of notoriety.
However, Rude does hold a special place in wrestling history, the first performer to appear on both RAW & Nitro the same night at the same time - Rude's WCW defection was absolute genius by Bischoff and company, totally pointing out how much more exciting a "LIVE" Nitro could be vs a taped RAW, plus it reallt was embarrassing having him trash WWE on Nitro at the same time he was appearing w/ DX on RAW.
Only way it would have been better was if he would have actually been able to get in the ring and perform, then it would have been epic, better than Luger showing up by surprise one night after main eventing SummerSlam. Personally, I thought it was about as good a "Gotcha" moment as either company had in the fued since Vince trotted out Bobby Heenan with the WCW Title belt to proclaim that "THe Real World Champion is coming to the WWF", especially since that giant gold belt was so linked in image to Ric Flair.
It was always odd to me that DX was fronted by two guys almost 40, one of which who had been wrestling for over a decade, and they were supposed to be the juvenile delinquents of wrestling - guess they couldn't find someone who might have been YOUNG to play the parts lol
As for Rude, staying in DX would have done little to help or hurt his legacy, he didn't accomplish much in WCW either but at least the jump itself was a priceless piece of wrestling history