I agree about the [uk] - interesting as the JEs give examples in kana.
Like Robin, I don't think we need an xref from one 強者 to another.

@@ -22,0 +23 @@
+<re_nokanji/>
@@ -31 +31,0 @@
-<xref type="see" seq="1506210">強者・きょうしゃ</xref>

Added one more [sK] form:
https://ja.wikipedia.org/wiki/武士
他に類義語として、侍(さむらい)、兵/兵者（つわもの）、
兵者	896
====

つわもの	88196	2.6%
ツワモノ	123424	3.6%
強者	300153	8.9% <-also きょうしゃ
兵	2871323	84.9%　<- also lots of stuff, somewhat hard to say precisely (but I'll give some more narrow results below)

兵達	28697	66.1%  <-- some of this are still へいたち probably
強者達	5268	12.1%  
ツワモノ達	4869	11.2%
つわもの達	4610	10.6%


揃い seems to be used to describe lineups of sports teams, and perhaps thus favors kana usage. (image search returns sports teams)
つわもの揃い	2685	20.6%
兵揃い	722	5.5%
強者揃い	5534	42.5%
ツワモノ揃い	4089	31.4%


Actually killing a soldier?
強者を倒す	388	20.7%
兵を倒す	1483	79.3%
ツワモノを倒す	0	0.0%
つわものを倒す	0	0.0%

古+... is a dictionary example usage...
古強者	3603	51.5%
古兵	2983	42.7%
古つわもの	108	1.5%
古ツワモノ	65	0.9%
ふるつわもの	233	3.3%

Another dictionary warrior usage:
歴戦の強者	1992	40.8%
歴戦の兵	1149	23.5%
歴戦のつわもの	891	18.3%
歴戦のツワモノ	849	17.4%

sankoku identifies 強者 as gikun,etc.  I think it is, not sure how to mark that without touching 兵.

added 兵者[sK]
added katakana form.
removed [uk] from [1] (questionable on [2], though there are definitely [uk] "contexts", like ツワモノ揃い sports teams)
===

夏草や兵どもが夢の跡 ー芭蕉
"The summer grass / 'tis all that's left / of ancient warriors' dreams". 


Was reading about rare kanji on reddit, and a small back-and-forth took place over this term.

https://www.reddit.com/r/LearnJapanese/comments/12jlwbj/when_is_the_kanji_鬽_for_bakemono_used_if_ever/

Assertion was "つわもの as a reading for 兵 is still pretty common and in use, you'll find it in books all the time. I can 100% guarantee you that literally every native speaker can read 兵 as つわもの." 

This was followed up with something that ties back to the haiku I independently discovered from the ngrams (below). "Especially when it's also part of a common poem/literary piece that most native speakers learn in school. Normally it's read as へい so yeah, if you ask someone to read 兵 out loud, they will likely read it as へい but つわもの itself is not that obscure of a reading." https://haiku-textbook.com/natsukusaya/

As comforting as it would be to think that the Japanese would kindly spell out such an obscure reading for us, I don't get the feeling that this is actually [uk], *at least* for the "warrior" sense. For example:
の兵は	10758	76.0%
の強者は	2627	18.6%
のツワモノは	504	3.6%
のつわものは	272	1.9%

furigana.info never reads 強者 as きょうしゃ (though the texts are older, and there are limited examples). They also say 兵 is 70% つわもの. (again, limited samples).

Stumbled on a famous line from Basho in the ngrams（too long for the whole line). Same one mentioned on reddit:　
夏草や兵どもが夢の跡

Here it is on a rock:
https://id.foursquare.com/v/芭蕉句碑夏草や兵どもが夢の跡/5d8f75c1bc26ed00082f5346

It's on a few rocks apparently.  This page includes a plaque with a description, including an english translation (brown sign, have to scroll down)
http://jin0506.s28.xrea.com/framepage5ao.html
"The summer grass / 'tis all that's left / of ancient warriors dreams". 

This is a scholarly Japanese translation, more notes here. Might be worth an entry.
https://www.mlit.go.jp/tagengo-db/H30-00188.html

Anyway, the associated ngram counts:
夏草や兵どもが	4603
兵どもが夢の跡	12503	34.9%

兵どもが夢	16197
強者どもが夢	1998
つわものどもが夢	5150
ツワモノどもが夢	638

Obviously Basho will tilt toward the original kanji, but the poem itself also influences people's usage.
===

Side note for Robin's consideration in particular. (I'm just going to put the xref back so that you need to actually remove something again if unconvinced).

It is perfectly natural to reach this entry by searching for つわもの, ツワモノ(how I got here), or even 兵.  If this entry is the result of such a search, you won't see the separate entry for 強者.  In these circumstances, you may come to the conclusion that the reading of 強者 is つわもの.  For me, the reason for the xref is not to elucidate the meaning of this entry, but to warn that the the particular kanji associated with this term has separate, not-uncommon reading/meaning.　This is of particular relevance for this term because you are most likely to get here from a search that does not contain any of the kanji from 強者.

I guess you could make that argument for 兵 as well, but I think it's usually more obvious that a single character with a long Japanese reading is also going to have other definitions/readings if you look for them.

I literally did a second search just to make sure 強者 had the separate, expected entry, but I wouldn't have always thought to do that.

@@ -13,0 +14,4 @@
+<k_ele>
+<keb>兵者</keb>
+<ke_inf>&sK;</ke_inf>
+</k_ele>
@@ -16,0 +21,3 @@
+<r_ele>
+<reb>ツワモノ</reb>
+</r_ele>
@@ -19 +25,0 @@
-<misc>&uk;</misc>
@@ -24,0 +31 @@
+<xref type="see" seq="1506210">強者・きょうしゃ</xref>

daij, meikyo, prog

I don't think the x-ref is needed.

@@ -19,0 +20 @@
+<gloss>soldier</gloss>
@@ -21 +21,0 @@
-<gloss>soldier</gloss>
@@ -25 +24,0 @@
-<xref type="see" seq="1506210">強者・きょうしゃ</xref>
@@ -27 +26 @@
-<gloss>courageous person</gloss>
+<gloss>person of courage</gloss>
@@ -28,0 +28,2 @@
+<gloss>very capable person</gloss>
+<gloss>master (in a field)</gloss>