We are talking about the German Mass in the Tenth Century and from what I've read it was not entirely uniform with Rome. Rome maintained many old traditions as did the other Patriarchates that were special to the Great Cathedrals. The Germans were likely already practicing the use of unleavened bread while Rome was very late, from all that I've read about this, in accepting this innovation. Studying Liturgical History involves a lot of speculation about large areas and large periods of time and often you will read people quoting speculative arguments for this or that practice being general in a given area as being proven fact for the whole of Europe which contributes to disinformation and angry arguing. This has only increased with RC historians who want to justify the reformed Latin Rite that came about after Vatican II.
All that I want to add to the discussion is that from the great story of St.Vladimir's conversion to Holy Orthodoxy we can learn nothing about the German Mass. From what little we know about the German Mass of this time is that it was likely modeled on the Roman Mass with many small differences. But we cannot and should not speculate because we don't know the Church, we don't know the size, we don't specifically know where, we don't know who served, the size of the choir, if the priests and or bishops were notorious for corruption and lack of piety and high in immorality? We don't know. What we do know is that Hagia Sophia was the most magnificent Cathedral in all of Christendom for hundreds of years with even its own variation on the Church services, the Asmatic Services, filled with iconography, beautiful architecture, a large magnificent choir, etc. It was a beautiful icon, when it was at its best, of the Heavenly Kingdom of New Jerusalem.
Nothing can be said about whether the German Mass or German Church Services of the time were more or less Orthodox from reading the Primary Chronicle. We could speculate endlessly about the corruption prior to the Gregorian Reforms in Germany or the lack of genuine piety in priests and bishops in feudalism and argue but there really is no point. The most traditional Masses of today are in Churches with architecture, furniture, iconography and Rites that differ a great deal from the German Churches and Mass of the beginning of the Tenth Century.