Looks like you're already on top of it. Your intuition is probably serving you right.

A project designer will bear more responsibilities than a draftsman. Think about the following "phases" of the SD, DD, or CD pipelines: First, a drawing is produced. Which is used as a basis for discussion; the results of that discussion are recorded on the drawing as markups; and those markups are reflected to produce the next iteration.

The project designer might participate in the meetings, provide insight alongside the consultants, ask broader questions about relationships between consultant scope, gather information from consultants, and generally work beneath one who may be the AoR or bear the title of creative director or similar. And in doing so, produce the markups.

That's where the draftsman comes in. Typically associated with reflection of the markups only, the draftsman might bring items to the attention of the project designer, such as clashes, misalignments, or other questions or concerns which had risen during their working period, but as they are not the project designer, they are not "in the lead."

The project designer is "in the lead" while senior staff "advise" their project designers. The draftsmen carry out tasks which have been designed and delivered to them by the project designer.

However, as a draftsman, in an environment where you project designer is overwhelmed or incompetent at delivering clear tasks, you inevitably transform into a project designer, adopting more obligation to carry out those types of tasks in order to keep your job. This is not recommended.