Most average Japanese really do not believe anyone is a ninjutsu master, any more than someone in western society believing someone is a medieval knight. For the sake of actual Japanese martial artist most likely Hatsumi or one of his previous students would most likely be the most knowledgeable on the subject. There is some controversy on Togakure ryu but there is controversy in a lot of koryu arts. It is very possible that Togakure were things taught to Takamatsu who synthesize pieces together and called it Togakure ryu. I would say even if Takamatsu did make it up from some books, his background in other arts his research and understanding the context would still produce a better source than Anthony. We do know that Takamatsu was soke in legit koryu arts and was more well known for kukishinden ryu I think in those martial art circles during that time. Don Roley did a translation of his work.