There is a huge difference in working with a team that you know will be with you for only a single project and a team that you know will be with you for still many more.
When you’re working with a team that you know will be with you for a long time, you may do what needs to be done to achieve a favourable outcome for this project, but understand the outcome of the sum total of all potential projects to come is just as important, if not more: setting the right precedent and ensuring goodwill among all (as far as is reasonable!) needs just as much attention.
But with the team that you work with for only a single project, you do what needs to be done to achieve the best outcome for this project without too much regard to how that might implicate future interactions with the team. Thinking long-term when you shouldn’t could potentially hurt the outcome of this project.
If you’re only going to be working with them for this one time, setting a bad precedent or upsetting one or another doesn’t matter too much.
(This post is more a reminder to me than anything else: last year I worked on several one-off projects, during which I was always in this “long-term” mode of thinking. I tried pleasing everybody and making sure I didn’t set poor precedents – “fairly” distributing workload, for example, to people whom I knew couldn’t perform, ultimately hurting the results of these projects.)