How does an E6 have 6 service stripes?

PO1 William Van Syckle - AF is the same way. They promote to fill slots. However many slots are authorized for manning in a certain field are what is filled. So, the sometimes 7 or 8 available slots in a career field, they select the highest 7 or 8 scoring individuals, and that is that. Try again next year.

SMSgt Matthew Hoyer - In the AF, E6 is possibly the hardest to achieve.

Can’t like this comment enough

I agree. I have served in several components of the US Army - WAC, USAR, ARNG, USA over a period of 34 years. Highest rank held was E7 for two years. Retired as E-6 because the USAR Bde to which I had recently been assigned cancelled my ANCOC registration - it was the same time as their scheduled AT and they didn't want a second year without a PAC supervisor. Promotion was conditional yet they paid no attention to the orders. Lost that stripe because they cancelled my slot. My uniform displays 11 service stripes.
Come to think of it, I should probably edit my profile.

MSG (Join to see) i loved overseas duty. Had as many if not more overseas stripes as he has

Back in the late 80's, the Army made it nearly impossible for 98C German speakers to be promoted. I had an E-5 with almost 10 or 12 years TIG. Luckily, they changed my POC NCO to be language immaterial and I could finally get him his E-6 rocker.

I was going to say the same thing as you CSM. Can't really count them, but he looks to have as many overseas bars as service stripes. That and the slow promotion MOS. He could also be a Guardsman. National Guard doesn't have the same "up or out" policy as AC. I knew many career SGTs and even SP4s. If there isn't an E-7 slot in your field, you don't get promoted. You can usually transfer to get promoted or change MOSs, but that possibly means long travel distances to drills, which some people can't manage due to family or work considerations.

Maybe he was an office worker?

SSG Randall P. - And he lost them when he was successfully court marshalled, reduced to E-1 rank, fined, and dishonorably discharged for desertion.

That not the same SSG. One is infantry, the other is not. I couldn't expand the first pic to see his area of expertise other than being a SSG with many service stripes.

SPC (Join to see) - A combat stripe is every six months in a combat zone. That is not an overseas award.

MSG Richard Medina - I could enough to see the MI Corps crest over the NCO's pocket. Depending on his MOS i know MI NCOs who have had it be virtually impossible to be promoted.