In the debate between egalitarians (or evangelical feminists) and complementarians, both sides sometimes try to ground social models in a Trinitarian template. But, in principle, there are four possible positions:
i) The Trinitarian persons are coequal while husband and wife are coequal.
ii) The Trinitarian persons are unequal while husband and wife are unequal
iii) The Trinitarian persons are coequal while husband and wife are unequal.
iv) The Trinitarian persons are unequal while husband and wife are coequal.
I myself think it’s a mistake to use the Trinity as a template for social roles. Not only is there a fundamental disparity between God and creatures, but the attempted analogy is disanalogous.
For instance, complementarians sometimes ground male headship in Nicene subordinationism. But how is that analogous? This is how that would cash out:
The wife is to the husband as the Son is to the Father.
But how is a father/son relation analogous to a husband/wife relation? A father/son relation is a male/male, parent/child relation.
If you’re mounting an argument from analogy for subordination, the logical analogy would be:
Humans sons are to human fathers as the Son of God is to God the Father.
By contrast, the Scriptural analogy for male headship takes this form:
The wife is to the husband as the church is to Christ.
1 Cor 11:3 is another complementarian prooftext. That analogy cashes out thusly:
The wife is to the husband
As the husband (or man) is to Christ
And Christ is to God
I do think this passage, along with some others, is sufficient to establish male headship in marriage. That said, it can be a double-edged sword unless handled with care.
i) Complementarians gloss kephale in terms of rank whereas egalitarians gloss kephale in terms of source. However, Nicene subordinationists also gloss kephale in terms of source.
But that places Nicene complementarians in a bind. If they wish to use this as a prooftext for Nicene subordination, then they play into the hands of the egalitarians. If, on the other hand, they wish to use this as a prooftext for male headship, then they forfeit the verse as a prooftext for Nicene subordination.
You can either be a complementarian or a Nicene subordinationist, but it’s hard to ride both horses.
ii) In 1 Cor 11, Paul does have a grounding principle: the order of creation.
iii) In addition, 1 Cor 11:3 is dealing with the economic Trinity, not the immanent Trinity, per se.