Not quite. The NT Greek used the term “episkopous” (or the appropriate form), which has the sense of an overseer and the modern English “bishop” is derived from that.
While the Greek “presbyterous” (or the appropriate form) is used to refer a broader group, “older man” or “elder”, particularly in a spiritual sense.
In the instances you cite,
Acts 11:30, 14:23, 15:02, 16:04, 20:17, 1 Tim. 5:17,19, Titus 1:5 the term “presbyterous” reads in the Greek and the NAB transliterates it as “presbyter”.
Acts 20:28 and Phil. 1:1 read “episkopous” in the Greek and are translated s “overseer” in the NAB.
1 Tim. 3:1 and Titus 1:7 read “episkopous” in the Greek and the NAB translates it as “bishop”.
I can think of no reason for this inconsistency of translation in the NAB unless it is to lend support for the use of the title “Bishop”.
So it is not Paul but the translators who interchange these terms.
While the Greek presbyterous (or the appropriate form) is used to refer a broader group, older man or elder, particularly in a spiritual sense.
Ah, but is not the presbyter the priest? A third ordained place, between the ordained deacon and the ordained bishop - as is used in the Church and in many Protestant denominations?
In my haste, I may have included the reference in Titus in haste.