Bench is available time that isn't assigned to confirmed work. It can support a new engagement only when the person meets that engagement's requirements. A company can have substantial unbooked hours and still lack a qualified workforce planner. Total spare time doesn't establish interchangeable capability.
Use the skill-gap view with the required proficiency and grade. Inspect whether an internal move can cover the role now, whether verified training could make someone eligible later, or whether a hire is needed. Don't change a profile's skill level simply to remove a gap from a report. Training is a plan until the proficiency is verified. Costs matter as well, but a lower cost can't make an infeasible match deliverable. The tasks ask you to separate hours, capability and evidence so a planning recommendation remains grounded in the people and roles that exist.