We only seed the 5 regional champs, the 2nd through 4th placers all fall in line based on how their corresponding regional champion gets placed. So for instance region 1 may have the #1 champ, and it can sorta screw over the bracket if region 5 has the second best champ, but is stacked at 2nd-4th with contenders
I personally know of one bracket that has 4 solid contenders, while another region doesn't have a single strong contender. But I understand why we do this. It keeps seeding quick and easy without a lot of fighting, and keeps regional #1's and #2's on opposite sides of the brackets.
Personally I'd rather seed top 8 overall and random draw the rest.