I'm not sure why you jump to executive involvement when I specifically stated two creatives butting heads. There's all sorts of stories where execs or someone came in and forced a movie to have, eg a giant robot spider in a wild west settint that didn't make sense but they really wanted one in some movie so they forced it to happen in one of the projects they were overseeing. but the sum of us is better than individual, so while there are solo artists out there, they're the exception rather than the rule.