I've actually hit grounders through 5-man upper level teams. As long as you hit the ball hard, it doesn't matter how many people are filling which holes, just don't cheat yourself and mis-hit the ball. 5-man infields make me nervous but focused at the same time. I know I have to really drive the ball because if not, you have a fast outfield that will get to lazy pop ups or an infield that you're almost hitting at all the time unless you can hit it hard enough to get it through before they have time to get to the ball.