The first version, Nottingham, was the one that they said was like a CSI show and had The Sheriff as the good guy. Crowe and Scott both have said that they hated the script.

2 and 3 are the same. The original rumor was that Crowe was playing both but it was a mix up. He "played both" because Robin Hood becomes the Sheriff for a moment in the script. It's not like Crowe was ever scheduled to play two different roles.

Then they brought in Paul Webb, a British playwright, and basically did nothing with his version.

Helgeland came back and mashed together/rewrote the scripts and we got what was on the screen.

In the end, the film feels like a rush job. The ending was very disappointing and rushed.