Goldberg wasnt booked in meaningfull top tier matches on PPV for most of his big first title reign. Hulk Hogan headlined the PPVs in July, Aug, & Sept, GB's first three months as champion. In the two biggest shows he had title defenses, he was a headliner but shared significant build and promotion time with Hogan again (Halloween Havoc, Hogan-Warrior & GB vs DDP) & with Ric Flair's return Starrcade 98 (GB vs Nash & Flair-Bischoff). Fact was, DDP & Nash were the only feuds that were given any major promotion during his reign, all those months as champ and for almost all of it he took a backseat to Hogan, his best feud and match (which he lost) only coming when Hogan took time off.
Dennis Rodman was a multi time All Pro NBA player with Detroit, winning championships with them in the early 90s. Later in his career he cultivated a highly controversial personna, wearing outrageous outfits, multi colored hair, married a Supermodel, in short he was a wrestling like caricature even before he joined WCW. Karl Malone was the anti Rodman, equally (if not more so ) talented but a very quiet, conservative, public image.
Kevin Greene was a multi time All Pro Linebacker & Defensive End, playing mostly for the Rams when they were in Los Angelos. His 160 career sacks are among the highest totals all time in NFL history. Greene made no secret of his appreciation of wrestling, especially when he played for Pittsburgh. There were even articles in the local papers discussing the friendly feud among players on the team who split into two camps during the Hogan-Flair feud (Greene piloted Team Hogan, linebacker LeVon Kirkland lead Team Flair). Flair met several players from Pittsburgh while appearing at annual charity events sponsored by the Post Gazette newspaper (where website columnist Mark Madden was a sports collumnist who also covered wrestling). After befriending some of his fans on the team he arranged for several players to attend a Clash Of Champions TV special held in Vegas (near the site of that year's Super Bowl, which Pittsburgh was playing in). Eric Bischoff thought WCW might get some mainstream media exposure if they promoted the team's attendance and use a player in some capicity (which they did w/ Greene jumping in the ring to save Hogan from a Flair-Giant beatdown). After Hogan turned heel and formed the NWO Greene returned to team with Flair in 1997 tag team match on a PPV held in Charlotte (Greene by then was playing for Charlotte's NFL team). In between he was recruited by Nitro commentator Steve 'Mongo' McMichael (former Starting defensive end for Chicago when they won the 1985 Super Bowl) to help him in his feud with Flair over his wife Deborah. It was supposed to be NFL vs WCW until Flair & Arn Anderson bribed Deborah to convince Mongo to end the feud and join The Horsemen.