If total time, Boeing time, or heavy time were the deciding factors for a hiring decision, there would be no need for an interview.
One doesn't know about a candidate until sitting down face to face, and in many cases, putting the candidate in a simulator or aircraft. Even then it's no guarantee of performance in the classroom, simulator, or on the line.
Choosing a candidate for a given job is as much about that individual being a good fit, once the basic qualifications are met. A candidate might have ample heavy, international, make-and-model, 121, etc, experience, but that doesn't necessarily mean the applicant is the best one for the job, nor the only one for the job. I have met candidates in class who came to the table with significant experience, including in type, but who were humble enough to know that they were there to learn that company's way, and that their prior experience might be a help, and might be a hinderance to learning the current company way. Not everyone operates the airplane the same way.
An old dog can be a useful dog, but an old dog that won't learn new tricks may slow down the whole pack. Finding a dog that blends well with the pack is an important part of that process.