I think it also depends on the size of the company/department. A company with 4 people might be looking to bring on a 5th to fill some specific role. In that case, the offer to the second choice depends on the response to the first. On the other hand, a department with 300 people might be looking to increase head count by 10-20%, in which case the offers to each person are quite independent.
Although the reality is that a lot of hires will still be hired by a manager targeting a specific need.
When I was hired the job description was even written for me.
I'm in more of a marketing organization but if I look around me, there are positions for vastly different skill sets, backgrounds, and preferences. Most of the people in the larger team couldn't do my job well and I couldn't do theirs.
