Although storylines between themselves are way too different, the design between each lead is in familiarity

From Big Bet, there's an articulate casino lead manager/founder along the way within the Philippines, alongside a right-man and clueless-but-follow-by-the-book & first-abroad-experience police inspector; whereas from Decoy, there's a bluff-but-dangerous con artist 'king' and ex-lawyer-turned-detective, which his traits turned out to calm-while-collect-thoughts and no biased judgment (put personal feelings aside for professionalism)

and the methods are quite similar to male leads themselves: Cha Moosik has his own influence right from the start (childhood, which is enormous), hence being eloquent, and full of pride to be communicated with all people; whereas Noh Sangcheon convinces his people and also, 'baits' aka victims, to believe his encouragements to buy the products on his pyramid-scheme journey

If you want to watch these Korean dramas, I'd suggest to binge-watch all of them, don't be like me (wait each week); so for Big Bet, start within the middle of March because that's when all eps from the sequel are finished; whereas for Decoy, mayhaps at the end of April for other 6eps of the sequel to finish