How to teach my pickup crew some new skills?

I've played pickup for about 6 years, but this year a finally joined a league. I learned a lot and want to pass on some of what I've learned to my pickup group without being an annoying know-it-all. (I certainly don't know it all)

They usually groan when I try to change something (i.e. changing our ridiculously small 5 yard end zones to 15-20 yards) but they eventually come around.

We get a wide range of people, from the very athletic to special needs. We aim to be welcoming to all skill levels, especially beginners, but that can be a challenge sometimes.

This week I ended up with a team that seemed pretty competent, so I took a chance I tried to teach them the force. It took some of them a while to get the hang of it, but I think it worked really well. We shuffled the teams a bit and I tried to get the new guys playing the force. We got beat for several points in a row and I started getting told that the force isn't working and we shouldn't bother with it.

Our core group of players is showing some real improvement this year and I want to help them continue to improve, but we want to keep it fun, casual, and welcoming to beginners. Am I wasting my time?