I think you're exaggerating a bit. Making movies is multi-disciplinary, where sound vs visuals vs set design are largely different skillsets at the higher levels. Sounds similar to engineering vs design vs product management to me.

Sure. But at least at my startup 3 of 5 founders are able programmers, two of five are able mathematicians (important to our R&D process), two of five have extensive strategy and financial consulting experience and one was a manager for a long time.

So... we switch hats a lot. In the last six months I've been (a) deep into research, producing basically Beamer slidesets; (b) implementing that research in Python; (c) spearheaded the basic product design process, albeit based on the whole team's insight (my lemma was "I'm basically an anthropologist trying to make sense of what everyone's been saying", although I made significant calls (d) pitching in with front-end programming in Angular when our third party provider pooped out and it got to crunch time and (e) spent deep time writing finance spreadsheets and valuation models.

It's a tight ship and I'm not even the most multi-talented person in the crew.

Hollywood isn't the only union in the world, and from what I can tell, it's unique in its manner of operation. Is there any other trade union which has "cards" like that?

Occupations aren't usually that narrowly defined. Hollywood is something of a strawman in debates about unions, but then - Hollywood is closer to Silly Valley geographically than most typical cases of heavy unionization.