Another reason to remove load groups where possible is they make it very difficult to preduct what effect depooling a db server will have on the query load over the rest of the section. Say a host has some weight in one or more groups as well as the main traffic group, and is receiving 15K qps. We can't tell from the DBA side what proportions of the incoming traffic correspond to what groups. Depooling it might spread 15K qps over all hosts in the section, or it might dump 15K qps into the other host in the same group as it.