Matilda of Saxony, countess of Flanders - NN mother?

Hermann I, duke of Saxony and Hildegard von Westerburg

Medlands has this:
The necrology of Lüneburg records the death "27 Mar" of "Herimannus dux"[231]. m firstly ODA, daughter of --- (-15 Mar -). The primary source which confirms the name of Hermann's first wife has not so far been identified. m secondly HILDESUIT, daughter of ---. The primary source which confirms the name of Hermann's second wife has not so far been identified. "Otto…imperator augustus" confirmed the donation of property "aliquando Bilingo nostro comiti…in Neletici…quitquid coniunx sua hereditarii iuris habere" to Magdaburg St Moritz by charter dated 28 Jul 966[232]. Duke Hermann & his [first/second] wife had five children:https://fmg.ac/Projects/MedLands/SAXONY.htm#Mechtilddied1008

So the problem is that he had two wives - names unproved:
x NN, poss ODA?
xx NN poss HILDESUIT?

And 5 children from them, but we don't know which belong to whom:

• BERNHARD (-1011) *LIUTGER (-1011) *MECHTILD (c942-1008)* SCHWANEHILDE (c945-1014) *IMMA ?