The differencebetween these four and the radicalz is that TNA let these people leave at their own accord, whereas the radicalz almost forced their way out of the company.
In terms of quality and interest there is no comparision. The least over of the Radicalz was probably Perry Saturn and he had a hell of a lot more going for him than anyone on the list above.
By the time they moved, Benoit was the WCW champion. Here you just have a load of X-divisioners, and not even the best ones. TNA draws less than ECW, so stealing their top talent is not worth the feather in the cap that taking WCW's talent, which at the time had ratings comparable to Raw's.
This kind of angle could still work, but you'd need much bigger players than these 4. If it was 4 from AJ, Abyss, Consequences Creed, Samoa Joe, MCMG, LAX , Beer Money and maybe Petey Williams then it would be good, because it would be taking TNA's top homegrown talent from under their noses, in exactly the same way that happened to WCW.
However, the amount of persuasion it would take, for the minimal impact it would make, means that even that probably wouldn't be worth it. Remember much of the Radicalz impact came from the fact that many former WCW fans, who had seen them before, were glad to see them again. Also, they brought some fans with them, particularly those interested in technical wrestling. The same wouldn't happen now. Chances are, if you are a TNA fan, then you have at least a casual interest in WWE programming.