People can still claim children without any evidence. I worked with a cook who claimed like 6 or 7 kids. He never filed taxes at the end of the year so he didn’t need a SSN for them.
back then you could file your taxes with 6 or 7 kids and no one would check
that is not the same as claiming you have 6 or 7 kids that will be filed on your taxes and then just never filing it. Once filed he would need SSN for those kids, or he would owe taxes