Poker auction - Precedence of hands
As the creator of the game, you can certainly change whatever rules you want. But consider that people will value the various cards on the relative strength of the hands they could go for. If you change the strengths, then they will change their betting patterns to adjust.

Ultimately, however, the real question is - do you need to change it? And by that I mean, as you playtest your game, do you identify that the precedence needs to change? When you're designing a game, you have to playtest, and then playtest some more, then make some tweaks and playtest some more. Game design is about 20% design and 80% playtesting. So what did your playtesting tell you?