I believe that it depends on the job and the nature of the work since you may not need highly skilled labor for the task and employees may be expendable. sounds harsh but we see this in jobs like technicians and people on the manufacturing floor. training may be a pain but a few days will get you someone as good as the last. Retaining talent for jobs that require talent is ofcourse a must bit i dont want to eco the others. Retention is only important when demand for the job is low or when the skills required are high