Disambiguating characters based on historical figures

Noticed that post #995421 has the tags ishida_mitsunari, ishida_mitsunari_(sengoku_basara), and ishida_mitsunari_(sengoku_musou). The latter two are tags only on that post.

Should we just use ishida_mitsunari for any character based on Ishida Mitsunari, and people can search ishida_mitsunari + whatever_copyright? Or, since the Ishida Mitsunaris from different copyrights are quite different in appearance (from each other and from the actual samurai ), should we go ahead and put copyright disambiguators on the character tags and use plain Ishida_Mitsunari if the actual historical figure is drawn?

(Obviously there are probably many tags in a similar situation, but this is just an example.)

Another example is sanada yukimura.
sanada yukimura - used for both Sengoku Basara character and Sengoku Musou character.
sanada yukimura (hyakka ryouran)
sanada yukimura (sengoku hime)

There's a combined tag plus two tags with copyrights, so it's not at all consistent.

http://en.wikipedia.org/wiki/People_of_the_Sengoku_period_in_popular_culture has a lot more examples, though of course it doesn't list which ones have danbooru tags.

I think it's better to have copyright disambiguators instead of combined tags, because the characters don't look like each other.

Anybody else got any input on this?

There are characters that are based on historical and mythical figures (if the artist intended to portray them as such), AND there are some characters (and even others like band, weapon, etc) that only adapt the names, like Gilgamesh.

As alegria suggested, copyright disambiguators are recommended as this is good for distinguishing characters. For example, some want to browse jeanne_d'arc_(fate/apocrypha) pictures without being tied to other namesakes, featured here.
If we use [character]+[copyright] mix, that would expand the tag search ([character]+[copyright]+sword/namesake/parody/etc.).

I'd support going with copyright disambiguators over using a combined character tag. Though I'll admit that doesn't necessarily clear the tag for just historical appearances. If an author does a genderswap and says the person is a historical figure, we still have to go with the author regardless of how different in appearance the character may look or dress from the common historical depictions.

The wiki for the historical character of course should have all the links to all the specific namesake/variant characters.

_(copyright) qualify the character tags. Leave base for the actual historical figure outside of the context of any anime/manga/game/novel franchise.