I've got 11,217 Cubs cards from 77 different brands listed on a spreadsheet. A random number generator picked five cards, one each from the past several decades. The RNG likes rookie cards today, picking two of them.
1950s / 1960s: 1952 Bowman #136 Gene Hermanski This card is actually a reprint of the 1952 Bowman set. I've got reprints of the '49 - '52 sets, and then start with the real things in 1953. Hermanski was a career part timer. He played in 99 games for the '52 Cubs, hitting .255 with 4 HRs and 34 RBIs.
1970s: 1973 Topps #21 Randy Hundley Early in his career, Randy Hundley was an ironman behind the plate. He set an MLB record in 1968 by appearing as a catcher in 160 games. By 1973, he was worn out. Knee injuries had really curtailed his playing time in a couple seasons and he was just not the same anymore. The 1973 season was his last as a full-time player, as he got into 124 games. He hit 10 homers and knocked in 43 runs, but his average dropped to .226. After the season he was traded to the Twins.
1980s: 1980 Topps #676 Cubs Future Stars None of these three had any sort of big league career. Geisel pitched in seven different season for three different teams and was a .500 pitcher. I've written before about the sad story of Steve Macko. Pagel was the most highly-touted of the three, which makes him the biggest bust of the three. He was the Cubs #1 pick in the 1976 June draft, but never lived up to the hype. His Cubs career consisted of three at bats over two seasons and he struck out all three times.
1990s: 1992 Pinnacle #466 Paul Assenmacher Assenmacher and his slow curveball was the workhorse of the Cubs bullpen in the early '90s. In 1992 he became the first Cubs pitcher to pitch in at least 70 games in three consecutive seasons.
2000s: 2004 Fleer #476 Trio Prospects These three have had better careers than the 1980 rookie trio, but nothing too dazzling. Wellemeyer was with the Cubs from 2003 - 2005, and had an ERA of 6.19. He later pitched for the Marlins, Royals, Cardinals, and Giants. His best season was 2008 when he was 13-9 for the Cardinals. Leicester has a decent 2004 season for the Cubs, going 5-1, 3.89, out of the pen. He spent most of the next season in AAA and was traded to the Orioles after that season. Mitre has had the most hype, but he too never lived up to it. He spent parts of three seasons with the Cubs (2003-2005) before being traded to the Marlins. He has since pitched for the Marlins, Yankees, and Brewers with little success.