How does an E6 have 6 service stripes?

easy. switched branches and Army took years to transfer his prior service. I know an E6 with 30 years time in service

PVT. why don’t you ask the SSG. Do you have a problem with the SSG?

Context is important. But, since he has three unit service awards and the other four do not, it raises questions. If they are in the same unit, they should all wear the same awards. If they are not, it means that he was in a unit that was awarded them and can wear them even after leaving. Since the man in the middle is of a significantly higher rank and the only one not holding a diploma or other document, it makes me think that he is there to support his Soldiers when they had completed a course.
Now, let's correct the two on the right with their headgear on incorrectly.

The military is ever changing and evolving and unfortunately it can toss a roadblock in your path. Years ago, when the army communications network switched from analog to digital, the mos structure and unit personal rank structure changed and the E7 positions were increased. The army started mass promoting for these positions. Then Clinton was elected as president and he slashed the military deep and moved many to the reserves and ang. This left the army with to many e7 in its ranks. We went almost 10 years before the promotions returned.

Lots of possibilities, PFC. I re-enlisted in the Army Reserve at age 47 as an E-5 after a 10 year break so I was an E5 with 4 or 5 hash marks. Retired at age 60 with even more.

It was a typo a stripe for every 3 years

6x18 do the math every 3 years you get a stripe possibly mean that the SSgt has 18 years active duty

I wouldn't worry about an NCO having six service stripes. What really angers me is the poser I caught wearing 20 of them, five special forces tabs, and has his ribbons out of order and some ribbons the Unites States Department of Defense NEVER AUTHORIZED. By the way, this poser was also wearing a Navy Seal trident on what he was trying to pass as an Army uniform.

He might be the bad ass that keeps your young ass moving without winning any popularity contest.

I'm a CPL with 9 years of service... Now I was IRR for most of those years but life had other priorities for me. I also hear that NCOs don't always want to pass SSG since they can still spend time with their troops vs being stuck in an office all day doing paperwork or the admin path.