I tend to stay rather vague or to minimize to more decent amounts. Make it sound more occasionnal. And make the combat part of the missions less central and important, like focusing on the things that are not really put into the spotlight in ingame missions, everything happening around, that kind of things.
I also like to derail the subject to what really matters usually : not the amount (50 battleships x 5000 crew members down) but the action in itself and what it implies (serpentis assets eliminated, people died, that was switf and decisive, or else).