>However, as it is almost impossible to tell a 17 and 23 apart from most angles I don't suppose it matters that much.
Well yes, but I have to name it. And I am not sure i can use a 23 in my little game just for a problem of "labels".
If I did, I suppose that in game terms all the performances are the same, aren't they? The same speed class (we change every 20 km/h), the same basic maneuvers (yes, Ni.23 was a bit heavier but we have to simplify with our system), the same toughness.