I think it is you that assumes too much.
Say to Ananias?
This is what Acts 9:6 says Jesus spoke to Paul..."Arise, and go into the city, and it shall be told thee what thou must do."
As they are the same thing, your objection is moot.
And it isn't written of when Paul received the Holy Ghost, just that he would..."And Ananias went his way, and entered into the house; and putting his hands on him said, Brother Saul, the Lord, even Jesus, that appeared unto thee in the way as thou camest, hath sent me, that thou mightest receive thy sight, and be filled with the Holy Ghost." (Acts 9:17)
Your can assume all you want, but it isn't written so we don't really know when Paul received the Holy Ghost.
Paul called Him "Lord", that is for sure.
Anything else is pure conjecture.
As he was water baptized, it was according to Peter's revelation from the Lord that Peter spoke in Acts 2:38..."Then Peter said unto them, Repent, and be baptized every one of you in the name of Jesus Christ for the remission of sins, and ye shall receive the gift of the Holy Ghost."
The unbelieving Jews were quite the "thorn" in those days...eh?
But thanks be to God, much good came from it.