Vallian "final 'm'"

Hi list,

In my language Vallian, original final "-m" changed to "-n," whilst the stem
form of words originally ending in "-m" retained "-m". However, I am also
proposing that, under the influence of a neighbouring language, animate
nouns gained an accusative ending -m, which did not change the status of
word-final "-n" in the non-accusative.

Explanation: Given a word "maran", "mother", the relevant forms are:

Nom. sing.: maran (including consonant gradation t -> r in closed syllable)

Oblq. stem.: matam(-e)- (no consonant gradation in open syllable)

Gen. sing.: matamen

Acc. sing.: matamem

Oblq. plur. stem: matami-

Gen. plural.: matamin

Acc. plural: matamim.

Is this credible?

TIA

Jeff