so youre kind of onto something here. Grant's DNA soup is specifically from former and current members of the JSA at the time, with his biological mother being Mary Pratt and most of his DNA coming from Martian Manhunter. however, two of his DNA "dads" are Dinah Lance and Oliver Queen, making him functionally kinda-sorta the Canarrow son and kinda-sorta Roy's kinda-sorta brother. unfortunately by the Devin Grayson "Titans" run, the whole DNA soup angle was kind of written out and Grant was more or less just considered the son of Al Pratt, so this never really comes up even when Grant outwardly expresses that he wishes he could've had Green Arrow as a dad.