And you are trying to make the gender specificity of Greek the defining issue, when it didn’t exist in the original Aramaic spoken by Our Lord.
No, I'm merely stating that Gender specificity is one more thing on the block that differentiates in Greek. The thing that you're couching and trying to dance around is the most obvious brought on by the conversation and the simple fact that petros has it's own meaning aside from petra. The words are different in their specific meaning. It's like having one word Man (that means specifically "male", but generically, human) and another word woman, (that means specifically female, but generically, human) and saying that there is no difference between the words because they both mean Human. This is the stretch that you are making. As a language professional, it is dishonest and decietful.
Furthermore, we have to ask a simple question, why the two words? It is the underlying question that must be answered.
First to say that two words aren't supported in the aramaic, we have to rule that there are no aramaic words for mountain or cliff which are meanings applied to petra in scripture. There are words in Aramaic for mountain, and for cliff. In fact, go here and plug the word mountain into the search and for me it pulls up 14 words. Put in Cliff and it gives 2, that's 16 and we've barely gotten started.
So, we must also look at the references in the NT:
Matt 7:24-25 "Therefore whosoever heareth these sayings of mine, and doeth them, I will liken him unto a wise man, which built his hous upon a rock (Petra). [25] And the rain descended and the floods came, and the winds blew, and beat upon that house; and it fell not: for it was founded upon a rock(Petra)."
Matthew 16:18 "And I say also unto thee, that thou art Petros and upon this Petra I will build my Church; and the gates of hell shall not prevail."
Matthew 27:60 "And laid it in his own new tomb, which he had hewn out in the rock (petra); and he rolled a great stone to the door of the sepulchre, and departed."
Mark 15:46 "And he bought fine linen, and took him down, and wrrapped him in the linen, and laid him in a sepulchre which was hewn out of a rock(petra), and rolled a stone unto the door of the sepulchre." -- see matthew 27:60 above.
Luke 6:48 "He is like a man which built an house, and digged deep, and laid the foundatin on a rock(petra!); and when the flood arose, the stream beat vehemently upon that house, and could not shake it: for it was founded upon a rock(petra)." -- dug deep (ie bedrock).
Luke 8:6 "And some fell upon a rock(petra); and as soon as it was sprung up, it withered away because it lacked moisture."
Luke 8:13 "They on the rock(petra)are they, which, when they hear receive the word with joy; and these have no root, which for a while believe, and in time of temptation fall away."
Romans 9:33 "As it is written, Behold, I lay in Sion a stumblingstone and a rock(petra) of offence: and whosoever believeth on him shall not be ashamed."
1 Cor 10:4 "And did all drink the same spiritual drink: for they drank of that spiritual Rock(petra) that followed them: and that Rock(petra) was Christ."
1 Peter 2:8 "And a stone of stumbling and a rock(petra) of offence, even to them which stumble at the word, being disobedient: whereunto also they were appointed."
Petros has it's own seperate meaning - and not because it's being used as a name. The word predated the usage as a name. Just as every one else here has a name which means something in the language from which it comes. The word doesn't lose meaning or usage just because it is used also for a name elsewhere. If there had been some reason to assume no difference intended, the author could have simply said petros twice. He didn't. Masculinity/femininity arguments are worthless as this is state of being. The sentence structure is modified for the gender of the state of being word used. The sentence structure is gender modified to support the differentiation in use. And, simply put, it would not have been problematic to call Peter by the name Petra, if that had been what was intended. For all the arguing about the appropriatness of using a fem. gender word to name someone, it didn't bother the Apostles a whit to refer to Jesus a masculine gender male as Petra. So one wonders why it is appropriate to call one man petra and not another. Peter is never referred to as petra - only as petros.
One can't say the difference doesnt' exist in Aramaic; because it does. Petra is used to denote mountains, cliffs, seplechres, bedrock, etc and some of those examples are in scripture that I've posted just now. Petros is not used properly to refer to this things. Petros would be a "piece of" a mass, not a mass. If a cliff side fractures and falls to the ground, the loose rock that falls is petros, the cliff itself is petra. One grounded one not. The passage doesn't say 'you are petros and upon this petros' which would be proper. Remember this is a state of being language where love is love is love; but all love isn't the same, thus there are like a bazillion different words meaning love in Greek to differentiate between the kinds of love.
The last point I would make is that Christ spoke at a minimum, three languages. Aramaic, Chaldee, and Greek. Christ had a skilled trade, remember, and the trade language was Greek. This is also the son of God who was filled with the spirit and displayed their gifts. Tongues is one of those gifts - the ability to speak in other languages. So to say that Christ spoke in Aramaic therefore the entire text must have been written in Aramaic is rather absurd. Indeed, one would have to find such telltale signs in every manuscript in the entire NT anytime Christ is quoted in order to sustain such a charge. It is not the case. From a scientific background, I cannot say that the text was not written prior in Aramaic. But I cannot either say that it was because it is somehow intuitive - it is not. The possibility doesn't make it a forgone conclusion. Nor does it produce the original text that it may be scrutinized for clarity.
Absence of evidence is not evidence of absence. But neither is presence of evidence, evidence of presence. An axiom learned from long study of Archeology and Egyptology. The point of scientific methodology is to keep people from selling silly notions instead of facts. Such silly notions are things like dilute whiskey is a cureall and perfect spot remover. It allows us to seperate the fanciful from the factual so that we don't have people running off at every notion - like say that Paul was the Greatest of the Apostles and led the others because he alone was chosen as a minister specifically to the Gentiles - the largest group of people on the planet, he was chosen by christ for that office, he was given direct authority to open the doors to the Gentiles, his writings far outweigh in number and impact those of all the others, He had the authority in him to correct Peter when Peter went into error... See how easily such nonsense gets started. All it takes is someone coloring a situation and reading more into it than is there and error is born. It is the goal of science to clarify by searching for facts - the testable and knowable - so that one may say certain things are true beyond a doubt and some things might be true or false but are not proveable either way and that finally some things are utterly false. As Humans we want to act on what is true beyond a doubt, investigate that which is not proven, and abstain from that which is false. So while it is instructive to say that it's possible Bethoven finished his unfinished symphony, it is'nt proper to sit down and finish it and present that as the finished work. While Fermat may have finished and misplaced his full last theorem, it isn't proper to sit down and write out on paper one's opinion of what that might have been and then say it was. It is no more proper to sit down and write something out in Aramaic and pretend it was the original for something that doesn't exist as an original but that became a Greek version. Absent an actual original, the only thing there is - is speculation. Some of that speculation may be good or bad. But it is nonetheless speculation - not fact. testing theory is testing theory - it is not the end result.