Wish me luck--My team plays "that guy"

After a 6 year hiatus from coaching football, I am back coaching my son's 4th grade team in our community in-house league. Our league has a philosophy of development over winning at all costs. The league has rules about playing all kids as equally as possible, playing defense ( head-up positioning, no blitzing before the snap), and running the the offesnive playbook.

This week we play the team coached by "that guy." He is also on the board and is the grade level director. During last season and this season his team has ened up with either better players, or noticeable fewer players as he is in charge of player distribution. During games he argues with refs, runs illegal defenses, and runs offensive plays outside of the agreed upon playbook (based on the high school playbook). His offense is all about running his own kid on almost every play. He plays his best players the whole game and only subs out his lesser players. He accused another coach of cheating when his own kid threw an interception. When others have tried to discuss the issues with him, they are either wrong (he did run a legal play), pleads ignorance (he didn't know, but does the same thing the next game), or just ignores them (doesn't respond, tells them to talk to someone else).

I am a competitive person, but also believe I have a responsibility to follow the league rules. I think it is going to be a hard game for me (my players will probably be fine). Pray for me or wish us luck. Any advice would be appreciated as well.