Suwa and Sabu trivia

[Junko Tanaka]

Dear all,
Since it's not unusual to find name-reading mistakes in publications (I've
just found another one in a magazine), I want to ask if anyone knows why
Director Suwa's (M/Other, Duo) given name reads Nobuhiro and not Nobuhiko
(in Japanese ????). It's a delight for film buffs to point that out, but
I've always wondered why. Is Nobuhiro how it should be read in real life, or
his "screen" name-reading? In other words, is there any word-play at all
here?
Also, why Sabu (dir. of Monday, Dangan Runner)? On IMDb, he is credited as
Tanaka Hiroyuki. Given that he is actor as well, it's possible he has
several names. Has he talked about why he goes by Sabu (and in katakana)?
Any lead would  be appreciated.
Junko Tanaka, Tokyo