It’s not a pension based their rank. It is disability which is not rank based. VA disability is awarded in percentages 10%-100%.
Disability is something completely different from a military pension. The one that I saw the VA statement for was not a rank of Major and it clearly said it was disability payments.
Back then I worked for an accounting firm that did taxes and the “brother” gave it to us as part of his tax paperwork although it’s not required because it doesn’t count for taxes. He is the one that told me about the others receiving benefits. He said the one elder told him how to navigate the VA system to be approved.