I'm catching up to this a bit late.
This is an important question. Which categories should veterans go in?
To organize my thoughts ...
I.) Military/Unit Classification
I think Allen is definitely right that categories such as "5th Regiment of Foot" make sense.
That's a simple and independent classification system. Military forces have always had these, so it's just a matter of figuring them out and knowing where people fit.
II.) Historical/Conflict Classification
So, if we have unit categories, do we need "veterans" categories at all? What's their value?
The basic benefits of categorization, as I see them:
1.) organize your own family history
2.) connect genealogists whose family histories intersect
3.) help historians who are researching specific subjects
Putting someone in an "American Revolution Veterans" category will have little value for #2 or #3, but they could definitely be useful for #1, especially when we can limit the display of categories by Watchlist. Many of us would like to be able to group our veteran ancestors. And many of us don't know their units.
Assuming we keep doing veterans categories, the next question is whether we should split them by country or side in addition to conflict, e.g. "American Revolution Patriot Veterans" and "American Revolution British Veterans" instead of "American Revolution Veterans".
I'm thinking that maybe we should not, i.e. we should just have "American Revolution Veterans", "US Civil War Veterans", "World War II Veterans", etc. Subcategorization by nation is being done in the unit hierarchy.
If there is subcategorization in the veterans hierarchy, maybe it would make more sense to do it by battle or engagement, if at all.
The way I'm seeing it now, the unit hierarchy would be based on military classification. The veterans hierarchy would be based on historical experience.
III.) Professional Classification
There's at least one other way to categorize veterans: By their job in the military.
I've done this, for example, with "Generals" and "B-29 Navigators".
I think there's value in this -- for #2 and #3 in my "benefits of categorization" above.
That's not to say I think we should categorize privates, corporals, etc. Unless it's a command role, e.g. general, navy captain, where the rank equals the profession, rank is irrelevant (plus, it's fluid).
If we categorize command roles like "General" should it be "American Revolution British Generals", i.e. with conflict and country? Or just "British Generals" or what? I don't know.
So many questions. :-)