How should we spell vehachonim?

Summary: A divergence among Masoretes about how to spell the word, in the context of the tribe of Shimon. That the Samaritan Torah, at odds with the masoretic text, is like one side in the dispute, does not really matter and is no evidence at all, for a reason I explain.

Post: How do we spell vehachonim, in Bemidbar 2:12? This is a matter of dispute between our Masoretic text and the Samaritan Torah. Thus:

To the right is the Masoretic text, where it is spelled והחונם, that is, malei vav but chaser yud. Meanwhile, the Samaritan text has it spelled והחנים, that is, chaser vav but malei yud.

A quick search across Tanach for these two spellings yields the following. Regarding the spelling והחונם, there is only this one pasuk, in Bemidbar 2:

במדבר פרק ב

• פסוק י"ב: וְהַחוֹנִם עָלָיו, מַטֵּה שִׁמְעוֹן; וְנָשִׂיא לִבְנֵי שִׁמְעוֹן, שְׁלֻמִיאֵל בֶּן-צוּרִישַׁדָּי. 

Meanwhile, a search for והחנים, as in the Samaritan text, yields the following four pesukim, all in close proximity:

במדבר פרק ב

• פסוק ג: וְהַחֹנִים קֵדְמָה מִזְרָחָה, דֶּגֶל מַחֲנֵה יְהוּדָה לְצִבְאֹתָם; וְנָשִׂיא לִבְנֵי יְהוּדָה, נַחְשׁוֹן בֶּן-עַמִּינָדָב. 
• פסוק ה: וְהַחֹנִים עָלָיו, מַטֵּה יִשָּׂשכָר; וְנָשִׂיא לִבְנֵי יִשָּׂשכָר, נְתַנְאֵל בֶּן-צוּעָר. 
• פסוק כ"ז: וְהַחֹנִים עָלָיו, מַטֵּה אָשֵׁר; וְנָשִׂיא לִבְנֵי אָשֵׁר, פַּגְעִיאֵל בֶּן-עָכְרָן. 

במדבר פרק ג

• פסוק ל"ח: וְהַחֹנִים לִפְנֵי הַמִּשְׁכָּן קֵדְמָה לִפְנֵי אֹהֶל-מוֹעֵד מִזְרָחָה מֹשֶׁה וְאַהֲרֹן וּבָנָיו, שֹׁמְרִים מִשְׁמֶרֶת הַמִּקְדָּשׁ, לְמִשְׁמֶרֶת, בְּנֵי יִשְׂרָאֵל; וְהַזָּר הַקָּרֵב, יוּמָת. 

That is not all. Strip of the connecting prefix vav, and we discover this is an even more popular spelling:

במדבר פרק י

• פסוק ה: וּתְקַעְתֶּם, תְּרוּעָה--וְנָסְעוּ, הַמַּחֲנוֹת, הַחֹנִים, קֵדְמָה. 
• פסוק ו: וּתְקַעְתֶּם תְּרוּעָה, שֵׁנִית--וְנָסְעוּ הַמַּחֲנוֹת, הַחֹנִים תֵּימָנָה; תְּרוּעָה יִתְקְעוּ, לְמַסְעֵיהֶם. 

מלכים א פרק טז

• פסוק ט"ז: וַיִּשְׁמַע הָעָם, הַחֹנִים לֵאמֹר, קָשַׁר זִמְרִי, וְגַם הִכָּה אֶת-הַמֶּלֶךְ; וַיַּמְלִכוּ כָל-יִשְׂרָאֵל אֶת-עָמְרִי שַׂר-צָבָא עַל-יִשְׂרָאֵל, בַּיּוֹם הַהוּא--בַּמַּחֲנֶה. 

Now, this means little. That the Samaritan text has it is only to be expected, based on its nature. The Samaritan text tries to smooth difficulties, and to harmonize ideas and spellings. Since it is spelled in this manner in proximity, even if the text were originally divergent, the scribe(s) behind the Samaritan text would emend it to match the others. Meanwhile, greater entropy within normal bounds can be a sign of authenticity. And lectio difficilior would then argue in favor of the Masoretic reading.

The Leningrad Codex is in line with our masoretic text as well, with והחונם. So too Codex Hilleli:

And the Lisbon manuscript has the same, והחונם:

Look closely to the right in the above picture, and consider the Masoretic note. That leita, there is no other, written so, as החונם.

Miinchas Shai discusses this. He notes that the Meiri writes that this instance is chaser vav. However, in all sefarim it is malei vav and chaser yud. And so too in Hilleli, והחונם of Shimon, and there is none like it, and the rest are written והחנים. And so too the Rama za"l writes regarding והחונם, that there is one solitary one in the Torah written with with a vav but chaser yud, and the mnemonic is והחונם עליו מטה שמעון, and the rest of them are entirely written chaser vav, and malei yud in their language. Also, the Masorah Ketana in the margin has them all chaser vav except for two -- והחונם of Shimon is chaser yud, while החונים in Gederot is super-malei. This is reference to:

נחום פרק ג

• פסוק י"ז: מִנְּזָרַיִךְ, כָּאַרְבֶּה, וְטַפְסְרַיִךְ, כְּגוֹב גֹּבָי; הַחוֹנִים בַּגְּדֵרוֹת, בְּיוֹם קָרָה--שֶׁמֶשׁ זָרְחָה וְנוֹדַד, וְלֹא-נוֹדַע מְקוֹמוֹ אַיָּם. 

End summary. So is the true girsa, according to what is apparent from books at the end of sefer Nachum, as not as we find in the Masorah Gedolah here, that two are written such, malei vav and chaser yud. (Then, we would need to find that other והחונם.)

Or Torah says something similar to Minchas Shai:

Namely, that despite the Meiri, many disagree and that the text in the sefarim is not like that.

That Meiri had a text parallel to the Samaritan Torah in the spelling is not so surprising. Given the harmonizing trend in general, it is quite possible that this variant arose quite independently.