Imo to understand the "orthodox" (in that case, including "Catholic" and mainstream "Protestant") Trinity doctrine one must not stop at the theology (stricto sensu, i.e. doctrine of "God") defined in Nicea (325) but follow the Christological sequel down to Chalcedon (451) at least. Because only through this (historically painful) development did the Nicene definition become relatively stable (and viable from both an ideological and "political" standpoint).
Iow, no Trinity definition can be understood apart from a Christology (and also a pneumatology, i.e. doctrine of the Spirit, although the importance of the latter is less conspicuous in church dogmatic history). You can't discuss the relationship of "God the Son" to "God the Father" without considering at the same time the relationship of "God the Son" to "the man Jesus". That's what Christology is about (one or two "natures," one or two "persons," one or two "wills" in Jesus). The "orthodox" solution (by the above definition) to this corollary issue implies the doctrine of hypostatic union, including the enhypostasy of the logos (the divine, uncreated Word assumes the human, created flesh as the only "person" in Jesus in spite of two natures) and the anhypostasy of the sarx (the human nature in Jesus is thought of as "personless").
It results in a logical distinction between two kinds of Trinity, the ontological Trinity (referring to the eternal relationship of Father, Son and Holy Spirit apart from the "event" of Incarnation) and the economical Trinity (referring to the "historical" relationship of God the Father, the incarnated Son and the Holy Spirit in the church) which must be theoretically thought even to be practically denied (as is the case in most "preaching" theologies such as Karl Barth's).
The WT criticism of the orthodox Trinity practically never explores this aspect of the doctrine, except to dismiss it as "too complex" in an anti-intellectualist way; while there is some merit (and certain popular efficiency) to this argument of excessive complexity, if one stops there it cannot claim to refute the doctrine as it really stands.