Having met a number of boxers, both amateur and professional, I can vouch that while some show the obvious signs of having spent time getting hit in the face, some do not. It all comes down to how skilful they were, how skilful their opponents were, who they actually met in fights and how the fights went - something that cannot be predicted in advance throughout a whole career. So although it would be unlikely that a warrior would reach the end of their life without any obvious battle trauma, depending on their role and history, it would be theoretically possible.
That's just talking about physical signs. Attitude, psychological and psychiatric responses also differ and may not be visible on the skeleton, but would affect the choice of gravegoods.
Of course there's no such thing as a must-have catalogue of war and fight signs that someone has to have to prove they've fought. But someone who fights in a leading position would also train fighting, and that should definitely leave some traces on the skeleton - the fighter's equivalent to squatting facets maybe.
Things like these are such interesting topics that it's only half-sad we will never know for sure. I like that it makes me think about rituals, facts, social standing, symbols, and the possible explanations for something rather unexpected. And getting to look at something from a different angle is always nice!