I've been the club ball coach with the player who one weekend, looks like Cy Young and throws 5 innings and 80 pitches and looks great. Next weekend, on the 15th pitch after giving up his 5th run, ducking line drives, suddenly has his arm hurt.
As the coach, I might 'think' I know what's going on, but when a kid says it hurts, you take him out. This is actually easy.
Worse, is when they shake their arm and look bad, you go out and ask and they say fine. Have the intestinal fortitude to say, "no you aren't, go sit down", call the umpire out and tell him your pitcher is hurt and the next kid needs adequate warm up pitches to get ready.
Never throw a kid more than twice in a weekend and then only throw a second time after a quick (<15 pitch) outting the day before. Never throw the same kid twice in the same day, unless he finishes one game and rolls directly into the next (i.e. he throws 6th & 7th and the next game starts within 30 minutes of the end of the first)
Make a plan, decide how the pool games will go, decide what you're going to do if way ahead, way behind, etc. Decide who will close, who is long, who is short with a lead or behind. Decide who will pitch Sunday. Who is #1, #2, etc. Know how good your team is and have realistic expectations. If you aren't going to play more than one on Sunday, pitch better pitchers on Saturday. If you know you're playing three on Sunday, don't pitch them on Saturday.
It's better to be wrong with good pitchers who haven't thrown than wrong with good pitchers hurt. Let's face it, parents are going to be PO'd no matter what you do, so do the best you can for the kids.
Sign up for two tournaments a month. I had a team that could play USSSA Majors with limited success and USSSA AAA with great success. I tried to sign up for one of each, each month. One long tournament, one short. I got my pitchers work every month and the better ones two outtings a month. The few times we played two long tournaments in the same month, led to injuries (not just pitchers).
I haven't been on this board that long, but I've never heard of a college recruiter saying, "You're a great high school player and I'd give you a scholarship today except when you were 11, you had this one outting where it looked like your arm hurt and you quit, so I'm giving it to the other kid..."
Just my opinions.