Other ponds have stocked the entire food chain at once and done just fine. There are advantages to stocking forage base first and then fingerlings but given what your goal is, to ensure some fishing time with Dad, I say go for it. I just lost my Dad and I can tell you spend as much time as you can with him, you and him will both be better for it.
But that's just one pond monkey's opinion.
Oh and a belated welcome to Pond Boss, we're glad you found us.
