2 of the 3 winning decks shown above play a large number of option and tamer cards, in security control fashion.
In Mamoru-san's deck, we see a total of 14 option cards, and amongst them 8 recovery cards. He runs maximum copies of Reinforce Memory Boost, having a large pool of candidates (14 options, 4 Defeats, and 2 tamers) to be put into security for control.
Mamoru also plays 4 copies of Tactical Retreat, which not only work wonders when hit from security, but also synergizes extremely well with Zwart Defeat. Since Zwart Defeat is now a "Gaia Force" when hit from security (when you have Mastemon in play), returning him to the security becomes invaluable.
In the case of Morio-san's deck, while he also ran maximum copies of Reinforce Memory Boost, he did not opt for Tactical Retreat but instead, relied more on deletion options.
Playing this deck in security control fashion made a lot of sense, since Mastemon is a LV6 Jogress which requires 2 LV5 Digimons in play, which can be obnoxiously expensive. However, with security control, the efficiency of memory usage becomes significantly less important, relying instead on expensive and big plays.
Remark: it is also interesting to note that both decks only run 4 to 6 copies of LV4 Digimons.