From my book written by OSensei's son, aikido is derived from three other arts. Daito-ryu being one of them and the main influence. Kito-ryu is also a contributor. Kito-ryu means up & down as said by the author. I forget what the third art is.
He never studied Kito-ryu, just a little Kodokan Judo with a young sho-dan. In the light of Stan's research, and in the light of greater knowledge of Daito-ryu, it's really untenable to assert that what Kisshomaru wrote is correct.