> The Chinese languages don't seem to be in stroke order (no expert here)
They are for me. In the Asia section, 中文 ["Chinese"] is listed first, followed by 吴语 ["Wu"] and then 粤语 ["Cantonese"]. Stroke order is first by stroke count and then by an obscure criterion that I don't know (and that, in my experience, Chinese people living in China also don't know), but stroke count is unambiguous and these are in order: 中 4, 吴 7, 粤 12.
Note that they aren't in alphabetical order: 中 Z, 吴 W, 粤 Y.
Japanese appears between Wu and Cantonese for unclear reasons.
It is sorted FIRST by radical and SECOND by stroke order. This is roughly equivalent to the Unicode codepoint sort if you stay in the basic multilingual plane. The order also puts literary chinese afer wu Chinese, which breaks with a pure stroke-count sort:
Dictionary lookup is done first by radical and second by stroke count. Collation is not. Stroke count is first.
For example, I have a book of 成语 stories that gives its table of contents in non-alphabetical order. (Since nobody understands the traditional ordering, I also have several such books that put their table of contents in alphabetical order.)
Note that 三's radical is 一, the first Kangxi radical, and that 一 is listed first. Your theory is wrong. 三 isn't even first among the 3-stroke characters, which start (among these) with 口.
Why did you make up a false answer to this question?
The Wikipedia sort for the languages is as I stated above, with Literary Chinese and Japanese between Wu Chinese and Yue Chinese. I explained why it was sorted that way, because radical is considered first. You could not explain why Japanese appeared between Wu and Yue because you insisted and continue to insist that radicals are not used.
I didn't say sorting is never done by stroke count alone. But I have seen radical+residual stroke count much more often than stroke count alone. Probably a result of the content I'm accessing. It's mostly Japanese and not intended for children.
The dictionary and non-dictionary sorting distinction that you make doesn't sound like a real thing. The audience, the country, and the number of items sorted are bigger factors. But you're not wrong in that stroke count is sometimes used alone.
> You could not explain why Japanese appeared between Wu and Yue because you insisted and continue to insist that radicals are not used.
I can't explain that because it's part of a different logical group, with its name written in a different script.† This puts it parallel to the Chinese options and to Korean.
> The Wikipedia sort for the languages is as I stated above
I took you to be describing the sort order for characters, not for wikipedia. Wikipedia doesn't obey that order either. You can check the page for Jiangsu, where all of the languages mentioned so far appear before the "Latin alphabet" style languages, but 閩南語 and 閩東語 appear after them.
† I also can't explain why wikipedia seems to have chosen 吴语 but 粵語, 客家語, and 贛語. Jiangsu is on the mainland... and so are Jiangxi and Guangdong.
> all of the languages mentioned so far appear before the "Latin alphabet"
> style languages, but 閩南語 and 閩東語 appear after them.
Could it have something to do with Minnan and Mindong Chinese articles being written in a Latin script, (despite the language name showing in both Chinese characters and Latin letters) ?
They are for me. In the Asia section, 中文 ["Chinese"] is listed first, followed by 吴语 ["Wu"] and then 粤语 ["Cantonese"]. Stroke order is first by stroke count and then by an obscure criterion that I don't know (and that, in my experience, Chinese people living in China also don't know), but stroke count is unambiguous and these are in order: 中 4, 吴 7, 粤 12.
Note that they aren't in alphabetical order: 中 Z, 吴 W, 粤 Y.
Japanese appears between Wu and Cantonese for unclear reasons.