If a company puts out an ad, is that the speech of the assembled individuals? Which individual is responsible for the speech? What if the individuals within a c

If a company puts out an ad, is that the speech of the assembled individuals? Which individual is responsible for the speech? What if the individuals within a company disagree with one another? There has to be some kind of separation of "individuals" and "entity". To only see companies as simply "people" I think is short-sighted. A company is so much more than that. If companies are truly entitled, as an entity, to protection of speech, how do any marketing/advertising regulations stay valid, period?