That'll work. God's holy spirit is Jesus in substance/flesh.
The Trinitarians I've met insist Trinity means three separate and distinct persons.
They are serious too when they insist God has a personhood. And worse, some, not all, insisted Jesus ascended back to the father as,and remains in Heaven , a flesh and blood man.
Yes, I don't know where they got that three persons definition.

Tertullian is the father that defined the Trinity in the 200's. He left the Roman church because it was too worldly and joined the Montanists who still had the Holy Spirit and were strict on behavior.
Tertullian:
“We define that there are two, the Father and the Son, and three with the Holy Spirit, and this number is made by the pattern of salvation . . . [which] brings about unity in trinity, interrelating the three, the Father, the Son, and the Holy Spirit. They are three, not in dignity, but in degree, not in substance (?) but in form, not in power but in kind.
They are of one substance and power, because there is one God from whom these degrees, forms and kinds devolve in the name of Father, Son and Holy Spirit.” (Adv. Prax. 23; PL 2.156-7).
The Arian controversy: They were excommunicated from the Roman Church over this:
Arius taught, in accordance with an earlier subordinationist theological tradition, that the
Son of God was a creature, made by God from nothing a finite time ago.
Sounds like the JW's liked their view.