URI load balancing, rewriting, and security oh my!

That's doesn't stop you from adding /uri3 to the first section although you'll have to keep that second section for /uri3 also. As I think you have, you could switch the first and second sections around and that should do the trick. To make it slightly more efficient you could also end both sections with a 'return' command to stop further processing of the iRule (if you switch them around) once a match is found.