There's no other way than joining them into an east group.
Now that shouldn't be a big problem if you use a well thought loop'ed script.
Let's say you have 15 resistance groups, and each groupleader is named: r1 - r15
Now you put all those guys into an array: res_array = [r1,r2,r3,r4,r5,r6,r7,r8,r9,r10,r11,r12,r13,r14,r15]
Now you need one east guy, let's name him: e1
The script should then look like this:
_i=0
#loop
_rleader = res_array select _i
[units _rleader] join e1
e1 join grpnull
_i = _i + 1
?(_i<15): goto "loop"
exit
Only thing you need to consider is that each of your resistance groups must not consist of more than 11 men.
:edit - btw - nitpicker could now answer that there's indeed another way than joining them into an east group, but
that would be e.g: let them start as west and join them into resistance group by setting resistance enemy to west from start
but it would be basically the same.
Or you could also use setCaptive but not really handy in your case.
~S~ CD