The Past Simple: 3A (JOOGSO) / 3B (QABO)

The Past Simple 3rd conjugation can be tricky. Up to this point, I have not found any specific rules for determining which verbs are 3A vs 3B. I have seen a trend with some exceptions.

3A: Verbs with vowel change when conjugated
The verb is 3A if: there are 2 consonants before the final vowel "o" (ex: baxso, cabso) [not including verbs with "yso" at the end ex: adkayso]; if there is a single consonant "k" before the final vowel "o" (ex: buko)
****Additionally, so far verbs which end in "ow" appear to also be 3A verbs.  They are different because these verbs are in a change of status (caddow=to become white)****
3B: Verbs with vowel loss when conjugated
The verb is 3B if: there is 1 consonant before the final vowel "o" (ex: cabo, dego, dhimo); if the verb ends in "yso" (ex: akdayso, dhageyso, etc.)

EXCEPTIONS (found so far): Words like "NOQO" [3B verb: to become, to return] do not have a vowel change for the 2nd person.  Basically it seems that if the 3B verb which ends in "o" also has the short vowel "o" prior to the last consonant (noqo, soco, doco)
Past Simple: waan/wuu noqdey, waad/wey noqotey, waannu noqonney, weydin noqoteen, wey noqdeen

DISCLAIMER:  Please understand this is NOT a proven fact, only a theory.

Pronoun/WAA form	3A Root Verb	3A Vowel Change	3A Suffix	3A Conjugated Verb
I / WAAN	JOOGSO	Change final "O" to "A"	-DAY	JOOGSADAY
You / WAAD	JOOGSO	Change final "O" to "A"	-TAY	JOOGSATAY
He / WUU	JOOGSO	Change final "O" to "A"	-DAY	JOOGSADAY
She / WEY	JOOGSO	Change final "O" to "A"	-TAY	JOOGSATAY
We / WAANNU	JOOGSO	Change final "O" to "A"	-NNAY	JOOGSANNAY
You All / WEYDIN	JOOGSO	Change final "O" to "A"	-TEEN	JOOGSATEEN
They / WEY	JOOGSO	Change final "O" to "A"	-DEEN	JOOGSADEEN

Pronoun/WAA form	3B Root Verb	3B Vowel Change	3B Suffix	3B Conjugated Verb
I / WAAN	QABO	Drop final vowel	-TAY	QABTAY
You / WAAD	QABO	Drop final vowel	-ATAY	QABATAY
He / WUU	QABO	Drop final vowel	-TAY	QABTAY
She / WEY	QABO	Drop final vowel	-ATAY	QABATAY
We / WAANNU	QABO	Drop final vowel	-ANNAY	QABANNAY
You All / WEYDIN	QABO	Drop final vowel	-ATEEN	QABATEEN
They / WEY	QABO	Drop final vowel	-TEEN	QABTEEN