I flew for a major U.S. Airline and after retiring worked for a major aircraft manufacturer. The manufacturer's checklists and procedures were based on safely operating the airplane. The airline checklists and procedures were based on safely and efficiently using the plane in line operations. Non-normals were the same, but normals were very different. Checklists were designed more to get the plane going and were much more efficient for line ops where things tend to change a lot at the last minute.