<<He was not included on any of her businesses (S-Corps and Schedule Cs). He wanted a lump sum of money (400k in this case), so she can keep all her businesses and whatever else she had.>>

This is settlement language, not alimony language. Alimony language would be to give income, not assets.

He wanted to be bought out from her ownership, not from her income.

Besides, it's post 2018, so it doesn't matter. Alimony isn't deductible any more.