I don't ever know if I've heard of the JYD signing as "catch and kill." If anything, I'd heard Vince considered him and Snuka as possible candidates to be the WWF;s champion during their national push before it became apparent that they could sign Hogan. Though that could be anti-Hogan after the fact speculation. They certainly marketed the shit out of JYD during the mid 1980s: making lots of action figures out of him and putting him in the Saturday morning cartoon.

As for Dr. Death, they did bring him into the WWF in 1998 with the idea of putting him against Austin. But the legend goes that him getting injured and knocked out by Bart Gunn in that pointless Brawl For All killed that possibility.