Did you see the "Sections FAQ" sticky up top?
You can use the share credits feature to make everything point to section 0 which means credits are essentially global. You then change the ratio for the different sections in the userfiles to be what you want...
Check out the 6.4 new "site change * nonleech <ratio> [<section>]" command to easily adjust the ratio of all user accounts who don't have leech on that particular section already. Or you could use the regular site change ratio command with the appropriate group/user flags or whatever to force whoever to a particular ratio for a section... Or of course use * to set everyone to 3, and then go back and set just siteops to 0 or whatever