Referring to Group of Differentiated Objects

Question

This is a bit esoteric, but it is something that came up recently when I was thinking about how to translate a piece of writing I have been working on for a while into Japanese. In any case, one of the things that I wanted to refer to were "four swords." Now, normally this would be 「四本の剣」or what have you, but I was wondering what to do based on the fact that three of them are western-style double-edged swords (剣{つるぎ}) and one of them is a Japanese-style single-edged katana (刀{かたな}).

Is this a case of majority rule, where we white-wash the katana in order to consider the four of them as a group, or is there an obligation to disambiguate, since saying

この刀は伝説の四本の剣の一本

is slightly confusing/awkward, at least to my eye. Is there any obvious choice between the two?

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This is a very narrow question, so I will extend it to:

"When grouping objects which are described using the same word in English (or ◯語) but are different words/use different kanji in Japanese, should they be split or unified based on the majority?"

There may not be a clear answer for this case, but it is certainly a more useful answer than my very specific question.

Answer 1

In general, I think ignoring minor items just because they are minor is not a good idea. Whenever you can, you should try to find a generic term which covers everything (3人の男＋1人の女→4人の男女, 5匹の犬＋2匹の猫＋1匹の猿→8匹の動物, ...)

In this case, there is a word 刀剣【とうけん】, which obviously covers all 刀, 剣, ナイフ and such. Of course you can just use unspecific 武器 here and explain them in detail in other sentences. That said, Japanese katana has often been considered as a type of sword/剣 in many fictional works. Saying この刀は伝説の四本の剣のうちの1本だ doesn't seem that odd to me unless you need technical/academic strictness.