Maybe you should elaborate more. That is not my impression, save for the impression that Irenaeus, like all Apolgetics of the pre-Nicene era, believed and taught subordinated Trinity. They all did. FWIW, I think maybe I should try to explain my understanding why this eventually became problematic.
Basically, the Word was seen as an expression of the Father (whom they identify with Wisdom, or Sophia in Greek, a very important Gnostic term, which in itself eventually became a problem). The way Christians looked at it, this great Mind of God cannot be wordless (as St. John of Damascus says, 8th century). Words express thoughts with force. Words can make things move, words can hurt, soothe, cut and build.
Thus the world was created, according to the Bible, by God through his Word – when he says "let there be light!" It wasn't enough for God just to think it; he had to actually say it for something to happen i.e. he creates everything by speaking (i.e. through or by his Word).
NB: I guess one could argue that we are all made in God's image because our psyche (or spirit, soul) has words; no other creature does.
So, rather than speaking of thee co-eqaul, co-eternal "Persons" (actually Hypostases which is not a person in Greek) in one divine essence or nature, the pre-Nicene Christian Apologetics speak of the Son and the Spirit as coming "out" of the Father, the Word being begotten (i.e. put forth, like our words are put forth from our mouths), and the Spirit "effusing" from the Father eternally.
Likewise, the spirit, of course, originates in the mind, and reflects the mind, but it is also "carried" and manifested by the spoken words. What is said also shows our disposition and intention and nature.
Thus, this early triniatrian concept makes God the Father the only "true" God (one who just IS for no reason whatsoever), the only one without a cause.
The other "two" are his divine realities which are caused by the Father. In other words, the Father is the cause of Trinity itself! Obviosuly, this God and his Trinity cannot be one and the same, let alone equal; he is the supreme cause of everyting and all, including his own divine Word and Spirit; he is the only one who just is. In other words, the early Christian God was still the God of the Old Testament, and his Word and his Spirit are simly his divine hosts.
The Nicene Council sought to erase this Apologetic Trinity, because under the pre-Nicene triniatrian formula, the Father was the only "true" God. By default the Word was divine (all that is of God is divine) but 'secondary' or lesser, even dependent on God (as he is often depicted in the synoptic Gospels) who does not exist without a cause, and is therefore subordinated to the Father. This inevitably leads back either to pagan polytheism, or back to monotheistic Judaism, which had to be stopped.
The whole purpose of the Nicene Council was to reaffirm monotheism without reverting to Judaism or slipping further into paganism with God the Father being basically no different than Zeus. So, a new triniatrian formula had to be found.
The "new" Christian God devised by the Council was now defined as one who only appears to us as three divine "Persons" (Hypoostases) in the economy of our salvation, but in his true essence (true nature, as he truly is) God is a simple and indivisible monad (singularity).
In other words, God chose to appear to us as three separate Persons, each performing a different aspect of our salvation, but that triad does not reflect God' real nature, which is indivisible.
The post-Nicene Christian God is understood as a single supreme deity and complete Mystery, inaccessible in his essence to human comprehension (ineffable), who in his love for mankind revealed himself as the Holy Trinty described by the Apologetics, so that our limited minds can know him.
Thus, the Son's and the Spirit's subordination is only an apparent 'economic' perception and does not reflect the true nature of how God really is, i.e. simple and indivisible. In fact, this new Christian God is the ultimate simplicity (and paradox, because he is also everything and all and beyond everything); God cannot be divided into 'parts' or 'elements.'
Thus, Christianity as we know it in the Catholic and Orthodox Churches, and most traditional or main-line Protestant communities, really began in 325 AD, follwing the Nicene Council. To cliam that the Church believed the same faith once dleievered "everywhere and always' is simply not true. The temrinology was the same but the concepts where not.
This inevitably leads back either to pagan polytheism, or back to monotheistic Judaism, which had to be stopped.
The whole purpose of the Nicene Council was to reaffirm monotheism without reverting to Judaism or slipping further into paganism with God the Father being basically no different than Zeus. So, a new triniatrian formula had to be found.
I think that is a perfect summary of what happened and what was happening to the early Church. Belief in the Trinity is not a Biblically stated doctrine of salvation. Protestants who accept the Trinity are simply behaving as a Catholic sect/cult that accepts some, but not all of the teachings of the Catholic Church. To pretend otherwise is not an honest appraisal of the history or the Bible - Catholic or Protestant versions.
What I think is missing from the modern doctrine is the concept of theosis. We read that Christ grew from grace to grace. It is a clue, I believe to a doctrine since missing from the modern Church. Catholic doctrine includes some sense of possible progress, even after death. Cannot the formula be: follow the precepts/behavior of Christ (works) and Christ will fill the gaps needed (faith) to in the end become an heir, a full heir with Christ? Am I misunderstanding something? What do you know or think about theosis?