[CB..]

if you use the mini tweaker---for the rudder drag--open the destoyers' SIM tweak file go to the propulsion set in the pull down list--and edit the

drag_rudder entry not sure wether it needs to go up or down (i thinkg G' explains it some where in this thread tho..) allso the prop_fact_rudder entry
which i'm guessing is how much effect the props have on the turning circle--

AFAIK your idea of copying a convoy and adding it at the end with a new RND_group number etc should work! give it new name as well to be sure--