There are a lot of youth infielders and outfielders that throw hard and are very accurate. But when they try to pitch they don't have the same velocity and then when they slow down their arm they can't throw strikes. Why? Pitching is a science. As a youth baseball coach, you need experience and an understanding of pitching mechanics to effectively teach pitching.
If you have never pitched or haven't watched good pitchers in high school, college or in professional baseball, then you must do research either on the internet, with pitching books or manuals, or go to pitching clinics in your area to get a working knowledge of pitching so you won't do a disservice to the pitchers on your team.
Some youth baseball coaches take the easy way out: overuse one or two pitchers while neglecting other pitchers who might not throw as hard but have pitching aptitude and can get hitters out by throwing strikes. Invariably these one or two pitchers burn out and get injured before they reach high school. Or, they have been used so much that they have lost some speed and location.
To solve the problem of pitching depth on youth baseball teams, all potential pitchers should warm up catching each other while working on the correct grips, lower and upper body mechanics, and the correct finish.
You'll be surprised how many pitchers you will discover and develop by this daily routine. Pitching can be very difficult to teach, but it is not impossible if you correctly teach it. Make it your challenge to learn it and convey it. You won't be sorry!