Haha! Yeah, I’m aware of Harrison’s claim. I don’t give too much credence to it though. He was doing Z-grade Italian genre movies before his stint in Hong Kong, so he didn’t exactly have the best reputation to begin with. SE-Asian schlock is the last refuge for established actors whose careers are on the downturn.

Thanks, the article you link is a fascinating introduction to Godfrey Ho and his technique:

Ho would splice together limited footage he shot himself (mostly just dudes in ninja suits hitting each other) with completely unrelated films of questionable origin. He’d record an English language dub track for the combined film that would attempt to thread a new plot over these multiple old ones. Some of the same footage was reused many times over in completely different stories. The bizarre results of these experiments have both enchanted and enraged cult film fans for decades. The ways Ho tried to mash unrelated films into one were astonishing and often very funny. For example, he’d use period footage as ‘back story’ or claim that unrelated characters were the same person, younger and older, again with flashbacks. He’d chop scenes together that had similar backdrops and have characters from two films appear to ‘talk’ to one another across the scene. They’d sometimes read newspapers with carefully cut-in headline shots that harked back to scenes from the other movie. Characters from one film would watch characters from another on a TV screen disguised as ‘surveillance footage’ or blackmail videos.

…

As the American-made Cannon ninja flicks with Sho Kosugi hit the big-time, IFD hatched their plan to ride the wave. Ho would splice his quickly-shot ninja footage into the incomplete films IFD had kicking around their archive. Lai would take the finished product to festivals and sell them under amazingly blunt names like Ninja Terminator, Ninja Thunderbolt, Ninja Destroyer, Ninja Dragon, Ninja In The Killing Fields (spoiler: there are no fields in this movie), or Ultimate Ninja. The important thing was that the footage they featured Westerners because this was what made it sell overseas.

Beyond the cast, Ho and Lai tried their best to appeal to English-speaking tastes. All their characters would be given comically over-anglicized old-fashioned names like Harry, Gordon, Bruce or Alan. American pop culture imagery littered the background of their films including, most famously, Richard Harrison – as “Ninja Master Harry” – having life-or-death conversations on an absurd Garfield phone (apparently Ho heard that Garfield was popular in America and figured this would be a cool thing for an American ninja master to own).

https://www.denofgeek.com/movies/ninjas-all-the-way-down-the-mysterious-world-of-godfrey-ho/

Unironically it sounds like Godfrey Ho was a genius.