Actually, no, most police departments, then and now, had their own dojo and were already training in some kind of Japanese Budo, many with much more established and recognized lineages.
Of course, there was some branding going on, that's fairly standard in Japanese Budo and Ueshiba participated in that as well, but I don't see it as a major factor for Takeda's target market.
Why would they be lifting Germans, anyway?
If the police departments had their own dojo and training programs already, then obviously branding is everything
with regards to Takeda, because why else would you train with a guy who would demand "would a bushi allow a technique to be applied to him?" There were no bushi and hadn't been for some time - bushi were a thing of the recent past.