Change group pin width with eaglecad?
You should be able to script this up in eagle's scripting language without too much problem. Something like this:

if(library(L)) {
    L.packages(P) {
        P.contacts(C) {
            if(C.smd) {
                C.smd.dx = 10; C.smd.dy = 30; /* or whatever */
            }
        }
    }
}