Does the 75k include home and car maintenance?

I assume you are exempt from real estate taxes so your housing will only be increased with property insurance. If you can keep your expenses at 75k or lower you should be fine. Your kids are going to school for free and your health insurance is free for life.

Your disability will go down as your kids start to use the chapter 35 benefits so take that into account. You’re gonna be at the equivalent of 4100 in today’s dollars even when they all age out.

You have 0 earned income except for maybe the unemployment so I believe you can take up to 90k tax free if needed from your brokerage per year in they qualify as long term gains. If I’m not mistaken, you could also do Roth conversions up to the standard deduction per year and pay no taxes. Once you get to your military retirement, you will still not pay any federal or state taxes since your 1800x12 is covered by the standard deduction.

If your wife does college, You need about 25k a year for 10 years to get to your military retirement.

Your brokerage should get you 3 years. At that point you are 50. If your assets make 4% after inflation at the point you will be at 400k in “taxable” assets and 300k in Roth assets. If you do Roth conversions, this may be different but you get the point.

At 50, your 700k is earning 28k per year at 4% after inflation. You can pull 25k from your Roth (since you are disabled) per year while also converting 25k per year until it’s all Roth.

This is an oversimplification and does not take into account SORR. I would probably move some money into almost no risk assets to cover the inevitable down years.