Re: Can we see that aikido is all over the place in MMA?
I don't really see the argument here anyway. "Young Grasshopper's" definition is fine and correct from one viewpoint.
Words have many definitions from different perspectives. His is quite physical and technical so from that viewpoint it is quite good and would relate in conversation to those looking for such.
Plus may I add 'Aikido is the art of peace' is yet another valid definition.