You know it seems either military people get out and they are a stickler for everything be orderly and neat , ( my BIL has basic stuff$ or they have a lot stuff.

My brother 4 years older had no mental illness, yes stress he managed grocery stores all his life , works like a dog ..he’s just a steady rock. I truly thought for a long time one of us was adopted lol .., he was the smart one In school and I killed myself to pass.

I hope that your brother will consider lightening the load. Maybe he is on the spectrum of Bipolar. Only thing you can really do is just observe and see if something is there