Workflows start out as a plan that HR puts together for all new hires in the company. The goal is to provide a consistent and measurable, high quality, experience that integrates the efforts of the new hire's whole team towards a faster ramp to productivity and integration with the company and team.
Once the workflow is set (its always being tweaked and optimized for the next cohort of hires), departmental or regional leaders may customize the workflow to account for regional or business unit differences. This could mean that language is altered, activities are added or removed all in an effort to optimize for the differences in business units.
The next level of customization happens at the manager level. Your manager can customize the plan further by adding in new custom activities specific to the needs of their team and the role. They may remove activities however, core activities may be locked. They also have the ability to edit activities and add extra resources to further dial in your experience, including reassigning and rescheduling activities to best fit your needs.
The last actor in the workflow development is actually you. Your feedback and comments are directed back to managers. They learn and listen and can pass feedback to HR to revise the core workflow. Your performance on activity completion also provides feedback to all levels to further dial in the experience. In short, there are dynamic components to the support built into the workflow that changes your experience from another hire's based on the intelligence we gather from your activities. No two experiences may be exactly alike.