This is business and production related.

Sigourney Weaver makes an appearance at the end of the film. I thought this was brilliant. Was it a calculated choice on her part or the producer's part to be at the end of the film, just prior to credits rolling?

Speaking of credits, her name came on first in three times the font of the cast. In fact her name appeared alone onscreen before the regular cast credits rolled. I was shocked and thought it egotistical at first. In hindsight, perhaps it was necessary to protect her A list reputation in a cast of aspiring A listers. Who makes that decision? Her agent?

I think that is what's included in the negotiation.

Terrence Howard must have had a really great agent starting out because his name during the credits was always made special, namely "The Jacksons" where he plays Jackie, the least famous of the brothers who is hardly seen in the film series.

If you ever read a contract for a big name actor, credit order, placement, size, alone/together with others, all of this and more can be included in a contract.