The problem is double jeopardy. There are circumstances where you might not be guilty of the worst one, but could be guilty of the lesser charge. For example, you might not be guilty of the murder, but could be guilty of all of the other charges.
If you're found not guilty, they can't re-try you on the other charges. So they charge all of the possible charges at once -- including charges that would be logically incompatible -- and let the jury decide which ones apply.
The judge has some leeway in deciding whether your punishment should be four separate charges added up, or less than that, depending on state law. They can also have you serve you sentences "concurrently", which has a kind of elegance: if you're serving four sentences for the same action, you serve all four at once, which amounts to spending as much time in jail as the maximum.
If you're found not guilty, they can't re-try you on the other charges. So they charge all of the possible charges at once -- including charges that would be logically incompatible -- and let the jury decide which ones apply.
The judge has some leeway in deciding whether your punishment should be four separate charges added up, or less than that, depending on state law. They can also have you serve you sentences "concurrently", which has a kind of elegance: if you're serving four sentences for the same action, you serve all four at once, which amounts to spending as much time in jail as the maximum.