You're the only one who ever sees the name. Or even the fact that you have a captain. If you don't like the name, use whatever name you want. Who cares?
Game Engine trumps role play might be why he cares, though your points are true also. Basically, if it was officially said what you said it wouldn't matter but except it might bug a few that it says otherwise though not a huge deal, but the devs don't always agree so just because you say it doesn't make it official policy. (Yeah seems dumb to have an official policy on something like this but doesn't mean it's bad to say, the official stance on this issue is you may role play your unit's captain with whatever name you please.)
