I coach this age group and yes their minds are sponges but each kids is different. I have some kids that know what every player is suppose to do on every play and some that only know their position plays. It depends on your skill set kids. I formation for the simple understanding then work up to offset I, then proset then single back wish bone. What I have do every year is start with I formation then work forward if I see the kids have it. Last year we had a our skill positions back so we just built on the year prior and had double shifts, motion, halfback passes, QB roll out to WR for pass, Wildcat. It was a lot of fun for the kids, but only because we could build from their learning.

I'm a strong believer in fundamentals with young players. Teach them the proper way to play a position when they are young. Then, it really comes down to talent. A good coach should also look at the abilities, the strengths and weaknesses of his players. Generally at this level most of the game will rely on running the ball, that is why an I formation or Wishbone is so widely used. But I've been associated with teams this young who had a kid who could throw the ball 20-25 yards down field. Which is great but wouldn't have done us much good if we also didn't have a couple of kids who could catch it (by the way, these kids have grown up and are now graduating high school, having won a state title and are all going to college on scholarship). But that is a special case. And when they were in early grade school league and able to complete 15 yard passes, it was highly effective but if we threw on every down then defenses would adapt.

So to re-cap, teach fundamentals and take advantage of the skill sets of your players.

if your skill positions are limited go POWER I lots of misdirection will keep the D on there toes

I would go with a Spread Offense. This will be the offense they will be using in High School for the most part. If the High School is not running it, They soon will.

I Coach 6-8yr olds I started out with the power I and then moved on to the Dbl pro-set the kids picked up the formations & plays pretty quickly and had alot of fun fooling the defence with misdirection plays & short passes.