One of things that must be understood about the Fathers of the Church is that within the writings of any one Father, there is bound to be something that can be construed to support a position that is not Orthodox. For example, in the fifteenth chapter of the first book of his treatise On the Holy Spirit, St. Ambrose states:
Learn now that as the Father is the Fount of Life, so, too, many have stated that the Son is signified as the Fount of Life (Ps. 34:9); so that, he says, with Thee, Almighty God, Thy Son is the Fount of Life. That is the Fount of the Holy Spirit, for the Spirit is Life, as the Lord says: ‘The words which I speak unto you are Spirit and Life’ (John 6:64), for where the Spirit is, there also is Life; and where Life is, is also the Holy Spirit.
There is a footnote to this passage in the Nicene and Post-Nicene Fathers wherein the works of St. Ambrose have been translated into English which observes:
In these words St. Ambrose appears plainly to set forth the procession of the Holy Spirit from the Son, though he admits that some consider the Father to be the Fount of Life, but he argues even in this case the Son was with Him.
This refers to the addition of the word filioque to the Nicene-Constantinopolitan Creed by the Western Church, which states that the Holy Spirit proceeds from both the Father and the Son. This addition and all its theological consequences has been roundly rejected by the Orthodox Church.
While one might be able to make the argument that the way St. Ambrose defends the unity of the Trinity lends itself to a defense of the filioque, it is only possible in isolation. This is why the Orthodox Church insists that no one Father be elevated above all the rest — taken as a whole, they help balance out each other’s failings while bolstering each other’s strengths.
For example, in his Letters to Serapion on the Holy Spirit, St. Athanasius plays with the same imagery as St. Ambrose:
While the Father is fountain, and the Son is called River, we are said to drink of the Spirit.
Notice how St. Ambrose emphasizes the unity of the Trinity while St. Athanasius emphasizes the diversity of the Trinity. Either one taken in isolation can lead to very different understandings of the nature of God; however, when taken together they each help us to understand that the Trinity is both one and three.