Probably has to do with being an Officer vs Enlisted. If you are higher paid and get a 3% pay raise and the lower paid guy gets 3%, guess what, you got more cash than the other guy! This has a snowballing effect whereas over the years you are making a lot more than the other guy. I do remember only once that the Officers got a smaller raise than the Enlisted, it was because the disparity in wages was so much, that they did it. It was a catch up for Enlisted. After that, back to the same routine where each got the same % raise. Go ahead compare the pay scales.
This gives Brazil a chance to jail the truly bad ones before the are released in their country.