Question:
It appears there are a number of counters that are not used in any of the scenarios included in the game.

Answer:
A:  Yes, there are a few and here is a list:

Insurgent/Spanish:
1x 3-8 Cav X                       Mar(Col)
1x 3-6* Inf III          TdI(Col)
2x 0-1-6 Inf II          I/TdI,IV/TdI(Col)
1x 1-8 Lt Arm II      S
1x N.52                   1F1      0/4
1x Bre.19                0A1      1/8
1x Vild                    1A1      1/F/9

Loyalist:
1x A-101                 1A1      1/9

German:
1x 7-6 Inf XX          Pol(SS)

Note that the Nationalist air units above may come into play when using 44H.  Similarly, use the Loyalist A-101 in place of the Bre.19 in the Insurgent OB should it go over to the Loyalist player.

Source:
[Official Erratum, 01-Jun-96]