OK, so just to be sure I'm getting this straight:
A Ranger (or any fighter with 2-wpn fighting) would look like this:
6th level (2-wpn fighting)
+2/+2/+2/+2 (+6 BAB, -2 to attack for multiple attacks, -2 for 2-wpn fighting, extra off-hand attack due to Improved 2-wpn fighting)
11th level...