Even the statement in the video is wrong: "Brahma CAN manifest himself in a suibstance or in a being", because Brahma IS manifested in substances AND beings.
Krishna and Christ are only identical in the view of the Vaishnavas, because they believe, that the first creation was made by Vishnu, who is according to them the "supreme souce of all creation" which is very similar to the depiction in the gospel of John 1, 1, according to which the "Word" (greek: Logos) Jesus existed before the creation and was the source of all creation.
I don't know, who copied from whom, but in terms of the Vaishnavas I can tell, that they are wrong at this point, because their believe contradicts Rigveda 10.90.5 (http://www.sacred-texts.com/hin/rigveda/rv10090.htm
), in which "Purusha" is according to Manusmrti 1,11 Brahma, while according to Manusmrti 1, 32 "Viraj" is begotten by Brahma and according to Manusmrti 1, 18 he is the source of the (following) creations. Thus "Viraj" is Vishnu!