A Missing Šumma ālu Snake Tablet?

Using Freedman’s reconstruction of the tablet numbers in series Šumma ālu, tablets 22 to 26 deal with snakes and tablets 30 to 31 deal with scorpions. Nothing is known of tablets 27 to 29. Tablet 22, and not in all witnesses, has a colophon that specifically mentions the tablet number Freedman assigns to it. The colophon of one witness to her tablet 23 numbers it tablet 21 (VAT 10481+) and another numbers it tablet 24 (A453+). One witness, the only one with a colophon, calls her tablet 24 tablet 22. No colophons survive from the very fragmentary tablets 25 and 26.
[Sorry for any confusion in how tablets are numbered. It isn’t my fault.]
I’m not interesting in debating Freedman’s reconstruction. There’s a lot more that goes into this than the numbering schemes of competing witnesses. What I am interested in is the contents of the her missing tablets 27 to 29. Did they deal with snakes also? Heeßel published several snake omen tablets from Assur. Of these his tablet numbers 9 (VAT 10481+VAT 10905b+ VAT 12918 etc), 11 (A 453+A 536+A2410+A 2438) and 12 (VAT 13812+VAT 13827) are duplicates or excerpts of varying lengths of Šumma ālu Tablets 22 to 25. His tablet 11 (A453+) is a witness to Freedman’s Šumma ālu Tablet 23. As noted above, it’s colophon calls it tablet 24 of Šumma ālu.
But what do we do with Heeßel’s tablet number 13 (VAT 10116+10145)? As such tablets go, it is very complete with 49 lines of omens on its obverse and other 43 on its reverse, almost all of them quite readable. Here’s a sample from line 8 of the obverse.

DIŠ MUŠ.MEŠ ina É.DINGER ana m[a-g]al ŠUB.ŠUB.MEŠ-ni šá NIR.DA-a SI.A ana É.DINGER ana É.GAL KU4-ME-ni
šumma ṣerū ina bit ili ana magal ŠUB.ŠUB.MEŠ-ni ša šērta malâ ina bit ili ekalli irrubūnni(?)
If snakes often(?) fall before me(?) in a temple, those who are extremely guilty will enter the temple (or) the palace before me(?).

Note: While the meaning is quite clear, it is unclear to me how to normalize ŠUB.ŠUB.MEŠ-ni or exactly what to do with the -ni after KU4-ME. For those abnormally interested in such things see the excursus below.
Lines 8-14 of this tablet plus a few other seemingly out of sequence lines deal with ominous issues involving snakes in a temple. Other lines deal with snakes in a man’s house, on his path, in a field, and otherwise on the ground. Some of the materials on this tablet has affinity with what can be read (and it isn’t much) from CT 40:25 which Freedman assigns to Šumma ālu tablet 25 but in so far as their parallels can be correlated there is no reason to think one is a verbatim of the other. It is not uncommon for a there to be near duplicate omens on more the one canonical Šumma ālu tablets. In addition, the other omens in this tablet from Assur are, as far as I can tell, without verbatim parallels in the extant portions of Šumma ālu tablets 22-26. It does not appear to be a Šumma ālu excerpt tablet. If the colophon of this tablet said it was some tablet number in the range 22 to 29 of series Šumma ālu ina mēlê šakin, no one would question it. But its colophon doesn’t say any such thing. Here’s what the final four lines (rev. 44-47) actually say:
44 [ . . . . . . . . . . .] x pi-i mPap-sukkal u mTa-qí-šá UM.ME.A
45 [. . . .. . . . ni]-ṣir-ti mŠul-gi AD.ḪAL UM.ME.A
46 GIM SUMUN-šú SAR-ma bà-rì DUB mdMUATI-PAP-AŠ A.BA
47 DUMU mdMUATI-MU-íb-ni A.BA BAL.TIL-u
44 [. . . . . . . . . . . ] to Amel Papsukkal and Taqiša-Gula, the scholars.
45 [.. . Secr]et of Šulgi, secret knowledge of the scholars.
46 In accordance with its original, written and collated. Tablet of Nabû-aḫa-iddim, the scribe.
47 The son of Nabû-šuma-ibni, the Assyrian scribe.
So what are we to make of this? The temptation is great to see Heeßel tablet 13 as a witness to an otherwise unattested canonical Šumma ālu tablet in the 27 to 29 range that for some reason or other became disassociated with the series as a whole. That the tradition of this tablet has some authority is clear from it being excerpted in at least two other tablets including STT 321-322 from Sultantepe. Without the support of its incipit appearing in other texts that also reference, in near proximity, other certain Šumma ālu tablets, I will try not to yield to this temptation but it will take a good deal of effort.
Excursus:
As I said, it is unclear how one should normalize ŠUB.ŠUB.MEŠ-ni. There is no doubt that the form is plural. It may also be a -tan- form, “continuously fall” Note CT 29 48:48, “Stars fell repeatedly(?) (ŠUB.ŠUB.MEŠ-ni) from the sky. (Oppenheim, 283). The simpler complex ŠUB.MEŠ-ni occurs in the protasis of an omen in the Assyrian Dream Book (K. 25+K.2046+ rev. I:1; Oppenheim, 283, 328), “If stars ŠUB.MEŠ-ni (fall) upon a man . . .” The phonemic or phonetic function of the NI sign is unclear in all such cases. I have tentatively rendered it in the line under study as a 1cs accusative pronoun (-nni) but who knows.
References:

Freedman, Sally M., If a City Is Set on a Height: The Akkadian Omen Series Šumma Ālu ina Mēlê Šakin Vol. 1 and 2 (Occasional Publications of the Samuel Noah Kramer Fund 17; Philadelphia: University of Pennsylvania Museum / Babylonian Section, 1998, 2006)
Heeßel, Nils, Divinatorische Texte I: terrestrische, teratologische, physiognomische und oneiromantische Omina (Ausgrabungen der Deutschen Orient-Gesellschaft in Assur, 1.; Wissenschaftliche Veröffentlichungen der Deutschen Orient-Gesellschaft, 116; Wiesbaden: Harrassowitz, 2007)
Oppenheim, A. Leo, “The interpretation of dreams in the ancient Near East, with a translation of an Assyrian dream-book”, Transactions of the American Philosophical Society, (New Series Volume 46, Part 3, Philadelphia: American Philosophical Society, 1956), 179-373