These five Cubs are the active players in the 170-card set.
Four more retired Cubs are also included. Notice how there are two cards for Billy Williams. The second card isn't a photo variation. Billy has two actual cards, #43 and #121. The 121 card is among the short-prints. Billy is the only player with both a base and SP card. My guess is that is a mistake. Someone forgot to double-check the checklist.
Night Owl posted earlier in the week about Panini reusing pictures in DK from year to year.
Hack Wilson is the only repeat among the four retired Cubs. His picture was also used in 2017 and 2018.