How do you assign specific training to employees with the same job title but varying training needs? For example, if one Operations Technician requires training on a certain equipment while another does not, how is this managed without role-based metadata? Are managers responsible for assigning such training?

unfortunately a lot of manual work to ensure people have the right training assigned

There are quite a few considerations here. As you say, the most straightforward would be to make managers accountable. Depending on the size of your organization and your tech set up, the most efficient would be to use a modern Learning Management System. These have features to capture, manage and address learning needs on an individual employee level, not just role-based level.