You couldn't ask for a better opportunity! If you continue playing with good travel teams, you will likely continue to hit harder throwers well. The big challenge as you move up is to become proficient at hitting a real pitcher who mixes well. This will always include a good off-speed pitch. You can use this "slow throwing" situation to practice the proper way to hit off-speed pitches.
You are thinking along the right lines, you just need to put a complete plan in place. Don't change where you are in the box. As soon as you recognize off-speed (in this case, every pitch 
), think oppo. Let the ball travel deeper. Anything middle/ middle away, try to drive it through the 3-4 hole on a line. Stay inside the ball.
You may need extra tee work with the ball back in your stance and away. Never let the barrel get below the ball. As you get better at this, you will find that when you are just a little early, your "misses" will be line drives up the middle. And with this thought process, your brain will tell you when you need to turn on an inside hanger and your timing will allow you to do so. Using this approach will help you tremendously down the road, not only with hitting off-speed but with your hitting mechanics in general and the ability to use all fields effectively. But, you have to be mentally ready to take a few steps back before you go forward. That means you have to be OK with looking bad sometimes in front of the guys that are on the laid back team.
Lastly, it is great that you are looking for help against this type of pitching. But never join in with the group that complains and uses it as an excuse ... "This guy is so slow I can't hit him". Coaches HATE to hear it and it IS an excuse. Be the better player. Again, nice job looking to find ways to be that better player!
