I believe that units are placed in formation in a growing spiral, so alternating your recruitment should indeed give you a much better dispersal of your "combined arms" squad - see Figure A.
Figure A:
987
216
345
Due to double digit numbers, I cannot expand the spiral further. Unless I go fully alphanumeric! - see Figure B.
Figure B:
PONML
A987K
B216J
C345I
DEFGH
