Is nikah halal with a razai(foster) sister's sister?

May Allah bless all of us. Dear brothers and sisters Assalam-Alaikum. I have a question regarding nikah. Whether the marriage of a man is allowed or not, with the younger daughter of his father's sister, who's mother (his aunt) breast-fed him only once before he get 2 years old with her elder daughter. The guys follows hanafi sect. And Abu-Hanifa's view (may Allah bless him with peace) is that even if a child is breast-fed once he is considered mahram. But other scholars and sects have different point of view about the times of breast feedings. So could you please give a right and brief answer? May Allah be our guide... Allah Hafez!