Im afraid I have no idea what the sentence is trying to say either  Cungan is a different person from Wang Gao  Wang Gao appears to be the maternal great grandfather or maternal grandfather of Nurhaci while Cungan is apparently also said by some to be an ancestor of Nurhaci but that is uncertain  With no source I dont really know what the sentence is trying to say  Personally I would just delete Wang Gao as it appears to have no relation to that sentence I have some books on Chinese history but right now Im preoccupied with something else so Ill have to check it another time