If you are speaking of: Disabilities that may be considered combat related include injuries incurred as a direct result of:
--An Instrumentality of War
If you cited one, but the board thinks your disabilities fall under another, I do not think you would be penalized. The evidence would be the most important element.
If you think your disabilities could be considered in multiple categories, say so in your narrative.
This might be of help:
DoD 7000.14-R Financial Management Regulation Volume 7B, Chapter 63 63-10 6306 DETERMINATIONS OF COMBAT-RELATEDNESS