How does an E6 have 6 service stripes?

Because the rules changed. I retired as an E-6 with 21 years then after I retired the big Army changed the rules for the draw down.

Couldn't agree with SSG Kemp more. It's perfectly fine to retire as a SSG. I probably will in about 3 years, and I'm fine wth that. E-6 with 18 years in? Standard data...

MUSTA BEEN BUSTED AT ONE TIME OR ANOTHER

General letter of reprimand will do it too. I've known a lot of really good NCO's that did something stupid as a specialist or something and got a DUI. With E-7 promotions done at DoA, it's not uncommon. E-6 to E-7 isn't particularly easy, some might equate it to Captain to Major in the officer ranks, 65% of all officers are Captain and below.

Could be like me 3 years in the USAR or NG before going active

I had a pretty nice stack, lol I was an E5 P when I got out. However sometimes you get stuck behind people who will just NOT RETIRE. Therefore you just keep chugging along.

We had an battalion commander, LTC, who was prior service E5. He was passed up one time to many and switched to enlisted to hit his retirement. It happens.

Prior service with time gap that required starting over at E-3 or E-4.
Speaking of E-3's, why don't you assume the Front Leaning Rest and contemplate the results of asking stupid questions.

You Serve you Earn the Stripes you serve Overseas you get them on the other Arm end of Drama...MilitantCrip if his Service is short then call him up and out him period full stop...

As a Company Commander years ago I retired a 20 Year Specialist. Not sure how he managed so long without separation but he was a great soldier. Though he had no desire to be an NCO. Nor would he have been a good one. But he was a damn good soldier.