Article 15 - how would you respond if PVT Snuffy made a good argument for a partially suspended punishment?

If its professional, fact based, devoid of emotion based reasons, accepts the act that got them there but articulates why lessor or no punishment would result in the same modified behavior (which is the goal of NJP)
Why not.....yes, though Id say less of an "argument" and more of a statement of mitigation.
By definitions it is an "argument I get that, but argument implies a back and forth, point, counterpoint..and I would find that inappropriate..
Following "do you have anything to say for your self?
I concise statement fact based, devoid of emotion based reasons, accepts the act that got them there but articulates why lessor or no punishment would result in the same modified behavior would be fine...IMHO

What type of Article 15? When I first joined the Army, and Article 15 was a badge of honor, just verified that people make mistakes. The issue is, can you recover from it? In the 70's an Article 15 was given the punishment served and it never left the Post where you received it. That was a good system. I can tell you that if you use NJP as it appears to be now, and you basically ruin a troops career for one mistake, you are making the mistake. Go back 40 years or so, and ask the current Colonels, CSM's and Seniors if they received an article 15, and if they learned from it? I got mine on the 1st day of Basic, After waking up at 0345 leaving the Reception Station, we went to our Company and ran and worked for the remainder of the day and the majority of the night. At 2200, we were given Fire Guard assignments, mine was at 2300 to 2400. I decided not to go to sleep, so I was on Fire Guard, a Turtle Head (Potential Drill Sergeant, who had not gone to school, but was assigned to the Company, but wore a Black Helmet Liner), climbed up the Fire Escape, came up behind me while I was sitting on a Footlocker, and asked me what I was doing, I said, Sitting. I guess that was the wrong answer (As there was no "Sergeant" attached to the statement. He tore into me, said I was sleeping, I was not, he said Sitting was the same as sleeping (I had never heard that before, but hey, I was new). Got an Article 15, $25 fine Extra duty and 2 weeks restriction (We were in Basic and restricted for the 1st 2 weeks). Should that have killed my career? No. Funny in the 70's giving an Article 15 proved the Commander had a grip on the things in his command (I used his because I was in the Infantry, and at that time they were all he's). In the 80's the dialog changed somehow and Article 15's somehow were a measure that you didn't have control. How times change. The Commander asks if there are mitigating circumstances, you should be able to present them

It's been a very long time, but I seem to remember that after a soldier is found guilty by the CDR the CDR then must ask the soldier if he has any matters of extenuation or mitigation that the CDR should consider prior to deciding the punishment. So that's the spot where a soldier would present a case for reduced or suspended sentence. It's also a time for the CDR to seek input on punishment from the chain of command. So I certainly wouldn't hold it against a soldier who presented matters that supported a suspended sentence. Of course, it's one thing to present thoughtful matters to be considered. It's another to say "come on, sir, do me a solid and I promise not to get in trouble again". ;)