After a bit of thinking the only technical issue I could find with the participation of those not listed as eligible for the combat bonus is that their participation may prevent others with eligible characters getting the combat bonus they worked for. For example, a Valor taking out a Redemption almost entirely by himself will not get his reward if the last shots are fired by a Ranseur, nor will anyone get any bonus in an opposite case if the last hit on the Valor is made by a Deimos. It would be useful and quite considerate from everyone to keep that in mind when participating in combat in Orkney.