Does it help or hender a soldier to be promoted to SGT without training in their mos?

Personally, I think it would hurt them. Professionally, it all depends on the individual and the job. Take for example my job as a supply sergeant. If a new Soldier, a 92Y PVT, comes to the unit and starts working in the PLL shop because it's undermanned, how is that Soldier going to know how to operate a supply room after the makes SGT? Can the Soldier learn? Yes, but they have no foundation to build upon.

SGT(P) (Join to see), I experienced this problem personally. I was a former 27D, Paralegal Specialist. My first duty station was at Camp Eagle, South Korea. As a PFC, I worked in an S1 shop in 2002-2003. Here are the issues that I had:

* Only 27D in the S1 Shop.
* Rest of personnel were 42As (S1 personnel)
* Closest JAG NCOIC I could speak worked 2 hours away.
* I worked three roles: S1, BN CDR's secretary (LTC Egbert), and the legal guy.
* I did not know what I was doing as a paralegal. I'm surprised my typed AR15's were never challenged.
* I had no mentor.
* S1 NCOIC did not cross-train anyone with my MOS, but forced me to do so with theirs.
* When I visited Camp Humphreys for two weeks of training, all I did was shred documents.
* Finally, my NCO (E5) gave me the NEEDS of the ARMY SPEECH.

The problem I encountered at Fort Hood (2003, my second duty station):

* I was the best Soldier I could be.
* I was behind the power curb.
* I became Soldier of the Quarter for CO, BN, & BDE.
* My NCOIC only worked at DIV's and Higher for 8 years (so never understood the problems I had).
* Finally, he gave me the "YOU DON'T KNOW ENOUGH SPEECH", which conflicted with what my first NCO told me as above.

In order to be promoted, I crushed every board and knew over 1500 flash cards verbatim in ABC order. I the board and my MOS as much as I could, but my NCO did not help me one bit. I did so well in winning the BDE board, the BDE CSM said he wanted to see me at the promotion board.

Basically, I was hurt not doing my job... but even worse when my 1st NCO didn't care and my second NCO at Hood did not bother to make a better leader in our MOS. I had to go above and beyond to get promoted (which really helped). The worst part was that my two shop legal NCOs put in their NCOER's (* Soldier won BDE Soldier of the Quarter) and did not even help me study one question and barely recommend me to those boards in the first place.

Now, it helped because I learned different stuff and helped me mentor Soldiers with my experience... but worked against a Soldier. This can be overcome by trusting more knowledgeable Soldiers that work for you.

Last I knew you have to the MOS in order to be promoted to the next rank or you were going to that school then you can get promoted. Again this was from April 2002-April 2011 in the National Guard. I don't know how active duty and reserves works and the same with National Guard now. Overall that would hurt the person. Especially when a lower ranking person knows more than you in that MOS. If that ever happens give the younger rank as much credit as you can. Respect. I've learn't a lot and still do from younger ranking Soldiers and even the Sailors. Although I've been out since April 2011 I know work at the sub base in CT the jr ranking Sailors are something else but all the same hardworking people trying to make a positive name for themselves.