stigma:
Luow-Nida =
scar, mark (of a slave)
Liddell-Scott =
st°gma st°zw the mark of a pointed instrument, a tattoo-mark, brand, Hdt., Ntest.
Beatings were often done with chords tipped with metal which made whelps and punctures of the skin. The greek term describes well the marks of a scouraging. And Paul proclaimed himself a slave of Jesus Christ.
There is no contextual support for miraculous scars. And Paul's own account of his beatings and claim to be a slave of Jesus Christ make the term very accurate without imagining these marks to be "stigmata" in the sense the term is used in this article.
I never said they were supernaturally produced marks nor do I believe so. I think you are possibly correct because in Galations 6:11-17 where this verse was found, Paul was arguing against those who would be circumcised to " avoid being persecuted for the cross of Christ." The implication being that by marking themselves by circumcision they are avoiding the marks of persecution for their belief in Jesus. But on the other hand the definition of stigma used for the word mark, implies that the wounds may have possibly been self inflicted. I only pointed out two possibilities in this argument (yours and that of self infliction) and neither promoted the idea that Paul had stigmata.
I am sorry if I didn't make myself clear the first time.