Help around understanding the concepts of workforce scheduling

Hello experts,

We are trying to implement the new Oracle workforce scheduling module and have referred all the material and implementation guide but are not able to get understanding on below basic questions -

1. Understand the flow of process on how assigning the patterns are impacting - if we assign work patterns does it indirectly relate to the work schedule assignment in the older way of creating work workday patterns and assigning it to work schedules and finally the schedules to employees? Work patterns would decide the schedule so we might not need creation of old work schedules anymore.
2. Not 100% of the population would need a scheduler, probably just 20%, how do we manage the other 80% without constantly have to schedule them?