Wolf,there were many Unitarian Christians in the early centuries of Christianity and people had different beliefs (Ebonites, Arianism, Nestorianism) but many were oppressed and their beliefs were distorted …history is always written by the powerful…so suggesting that Mary was trinitarian is not based on strong evidence.
Careful, you may inadvertently admit you hate Allah.

Do you know why I say this? Because you seek to give credence to the early heresies, many of which were Gnostic in source and believed in a semi-polytheistic understanding of the universe, or denounced God in some way, shape or fashion. The Marcion heretics, which are cited by many Muslims as an “early Christianity,” believed the Old Testament God to be
an evil demiurge. Both Muslims and Christians agree that the God of the New Testament is the God of the Old Testament, therefore it’s simply hilarious to me when Muslims cite the Marcionites as some brave early form of true Christianity, indirectly supporting the notion that
Allah is an evil god. Arianism likewise taught that Jesus was a form of
demiurge (or in the very least, a lesser divine being) in a belief similar to today’s Jehovah’s Witnesses - again, hardly complimentary to the Muslim view of God. Nestorians, while disbelieving the connection between Christ’s divine and human natures, were still Trinitarian to a large degree - again, hardly complimentary to Islamic theology.
In fact, few of those heretics were “oppressed” or “their beliefs distorted.” The Arians, for example, nearly took over the empire, and Saint Jerome later wrote that the world was shocked to wake up and find itself Arian. Most of the persecution, in fact, was committed by Arians to Orthodox (Saint Athanasius, Bishop of Alexandria, was exiled from his position five times by Arians). You’ll find if you study early church history that most of the persecution was done
by heretics, not
to heretics. The days of the Spanish Inquisition didn’t come until much later, after the Schism.
Of course, most of the people you mentioned (Arians, Nestorians, etc) came much later than the post-apostolic Church, which was led by men who believed in the Trinity and in the divinity of Christ, as well as salvation from the cross. Saint Ignatius, Clement I, Saint Irenaus, Polycarp, Justin Martyr, and many many more attest to this. In fact, from the time of the apostles to the time of Mohammad we find a steady chain of orthodox and catholic thought. What Saint John Damascene writes in the 8th century is identical to what was being written 600 years before him.
This was one of the reasons I left Islam - because I recognized that there was no apostasy like Mormons and Muslims believe in. I saw that there was no single event in history where we could say the Christians had distorted the word of God, because there was that consistency recorded in history. In order to avoid this, one has to be intellectually dishonest by playing the “What about the heretics?” game, or using atheistic apologetics, ignoring that those same atheists would most likely denounce Islam as well.
The fact is, in any case, pointing to disagreements is a logical fallacy that holds no water. It can easily be used against Islam - does the presence of early apostates or heresies in Islamic history prove that orthodox Islam is a lie? Does the presence of Ahmadi Muslims mean that orthodox Muslims are wrong? Does the presence of Shi’a mean the Sunni are wrong? Of course not. Dissent in and by itself is not evidence that a particular side is wrong.