8-ball, you are solids. What do you do?
If you said pocket the 2 and break up the 5-8, give yourself a cookie!
But what about shooting the 3 and breaking the 5-8, is that not just as good? Look at the situation this way: what if you do not break up the 5-8 clean, and you leave yourself no shot on the 5. Then what? If you shoot the 3 in, you give yourself no shot to continue. If you shoot the 2 in, you still have the 3-ball to shoot at in case things go bad.
So getting to the point: any time you are going to run into a cluster, don’t rely on getting a shot on a ball in that cluster. Always have insurance ball(s) sitting somewhere as a backup plan. This is why it is important to break up clusters early, you usually have insurance balls to help you out of a sticky situation.