I can't believe that parents would go up to a coach in the middle of a tournament and ask to see their kids batting average(most know already anyway). You don't say if the third hitter struck out 8 times or if she hit a bunch of HH balls that were caught. Maybe it was his kid, or maybe he's coached her for 5 years and knows she's a good hitter just had a couple of bad games. With all that said, he shouldn't have taken it out on your kid. I keep score for our team. If the coach asked me a question I will answer and will sometimes say number 12 for the other team has 3 triples so far, but I would never suggest the batting order. IMHO you were wrong to do it during a tournament.
I missed the parents asking to see the batting averages during the tournament. I would not have let the parents see it during a tournament. Afterward, in discussions with the players, I can see making general points with the team as a whole and then discussing improvement that need to be made with with player individually but not the parents at the 18U level.
The AC's job with the stat's is to point out things the HC might not see or think about during the games. Now if the HC gets mad over a private conversation with the AC the HC is in the wrong for the AC doing his job. If the AC was showing the stats to the parents during the tournament, that was wrong on the AC's part as it can only cause problems.
The coaches job is to discuss things during and after games to try to correct problems with the team. If the coaches have different opinions, things can be tried both ways to see what works for the team. The team is the most "Important" thing. Not the coaches ego's, not the parent's expectations, or the girl's ego's. Me, Me, Me does not ever work in a team game.
As a former coach and now sideline parent, you can't help but think what would I do in this situation. But as a parent, you can't stir things up that hurt the team. I don't talk to other parents about playing time or positions since it will always lead to problems in the end. Now if someone point blank asks you something, it is harder to dance around an issue. Everyone reaches a point where they have to decide to stay and grin and bear it or leave for what you hope is a better situation for your player.