all wings connected to the same consoles share the same assignment. if you want them to be different you will have to make them show different fader pages. to do that, keep [FaderControls] pressed and wait a second, then you should see all your fader wings show you in the displays that you can change the fader page by pressing one of the bump buttons. remember that a fader page is always 10 faders wide, so a 2x20 needs 4 pages.
you could leave your 1x20 where it is, move your 2x10 to fader page 3 and your 2x20 to fader page 5 so everything is separate.