Having worked closely with some dramatically different intelligent people, I really think intelligence and reasonableness are very different.

Being reasonable, is being someone with a strong genuine value for collaboration. They actively advocate for and work with others to optimize situations taking everyone's needs into account. Encourage give and take, constructive debates, and appreciate feedback. Etc.

An intelligent person can be all those things. Or none of them - but manifest them enough that, with some spin, they seem reasonable, while actually optimizing the environment primarily for their own long term benefit.

Very intelligent unreasonable people are disasters to work with.