Food stamps are different. People who are mandatory to a household budget (biological and adopted children up to age 22 have to receive with parents, and those with common children under 22 must receive together) and those who purchase and prepare meals together must be on one SNAP budget per FNS/USDA policy. Program eligibility differs across programs depending on how the programs are funded. The policies are all public and can viewed on DHS website. If income calculations were incorrect for someone you know I’d suggest they reapply and file an appeal if denied again. A common problem I also see is people listing partners as “husband” or “wife” and children in the home as “stepchildren” when they’re not actually married.