Brown was one of the first mma fighters that really called my attention when i 1st started paying attention to mma, back in 2009. His resilience was/is top notch, i can't really explain his 3 losses in a row back in 2010, but i have this feeling he was experiencing rough times in his head. I have Brown breaking top 5/10, if he can keep his mind in the right spot.
Top 5 is a huge huge stretch. The people in the top 5 are above and beyond better than Matt Brown. He could stay in the top 10, but I can't think of a single person that would be considered a top 5 WW that Brown would even almost beat.