Where are you getting the Fuji TV is a bigger producer from? The fact that Toei Animation handles all One Piece Foreign efforts should be enough to indicate otherwise.
A Television channel having a percentage, a really minor one, is not out of ordenary and it doesn't mean much. Fuji TV invest a ton of series together with Toei Animation, and they would like to get a assurance and extra money from their partner, as well as support it. Toei Animation has huge partnerships with Fuji TV and TV Asahi and many sponsorship relations with Bandai Namco, and so all of those have small stocks in the company:
Toei Company (32%)
TV Asahi (14.29%)
Fuji Television (7.14%)
Bandai Namco Holdings (2.00%)
Sony (1.86%)
The rest is Public Stock!
Yep, One Piece Film Gold has a Production Committee constituted with those companies, what is the point of that part of the post?