I don't know, but I never claimed Jesus was less than God. If you're referring to others who posted here, then, I don't agree with them. Although I don't know the answer, maybe begotten in this context means that He is unique or resurrected, as others have said either here, in sermons I've heard, or in articles I've read.
All three persons of the Trinity have equal authority and power, those being infinite, but as the God the Son proceeds from the God the Father, so also the God the Holy Spirit proceeds from God the Son, and they have chosen to operate according to certain roles. But I could be wrong.
So, if I'm wrong about that, I invite anyone who wants to correct me to correct me.