I did exactly what you're talking about; bought a house on a VA loan while separating with my follow-on employment at a regional.

It was a bit of a pain to show the loan guy what my income was going to actually be. I sent them a copy of the contract for the regional I was going to be working at, which showed both the pay scale as well as monthly hourly pay guarantees, etc. I created a spreadsheet that showed what my minimum annual income was going to based on the contract, but the bank wasn't satisfied with it.

I eventually had to contact the regional itself, which had a contractor they employed to verify employment. That contractor was able to produce a document that said basically the same thing I had previously done, showing the minimum income that the contract guaranteed for the first year, second year, third year of employment. Since it was on company letterhead, I guess, the bank accepted it and I got the loan.

Of note: I closed on the house before I left active duty and it didn't make a difference in the process. The bank wanted documentation of continued service if I was going to claim my military income in obtaining the loan. This isn't their first rodeo.