For balls going to the middle, it's usually better for the person diagonal to the person who hit the ball to return that ball, regardless if it's back hand or forehand. However, communicating with your teammate is still very helpful.
If its a quicker shot, is general rule of thumb forehand gets it? Even if its more towards backhand side? I just started playing but the hardest part (epsecially if playing with a random partner) is knowing when to go for it.
What they need to do is avoid yelling across the net at their opponent like a sports illiterate dumb a$$. You slapped the ball and won a point. Shut up and move on like this isn’t your first rodeo.