Coach, that's how we do it. However, you have to really be organized with cage time and rotations. NO, it doesn't bring the varsity down. However, the JV/Varsity does need time to be on their own. For example, on a Saturday, have the JV come in early or late. On the week, they need to be able to do their own infield without the varsity. You might have to find an open field for the JV to go do some work on 1st and 3rds or bunt defense or... You need that same time for varsity. You can't think of it all because something will throw your schedule off. However, if you have some type of plan, they'll do fine.