For the husband is the head of the wife (hoti anēr estin kephalē tēs gunaikos). “For a husband is head of the (his) wife.” No article with anēr or kephalē.
As Christ also is the head of the church (hōs kai ho Christos kephalē tēs ekklēsias). No article with kephalē, “as also Christ is head of the church.” This is the comparison, but with a tremendous difference which Paul hastens to add either in an appositional clause or as a separate sentence.
Himself the saviour of the body (autos sōtēr tou sōmatos). He means the church as the body of which Christ is head and Saviour.