It’s also something that happens in real navies and the coast guard.
Sending a candidate for captain or first officer to shadow on another ship before a command level promotion is regular practice. In some cases, they are expected to complete shadowing on as many as two or three ships other than the one they regularly serve on.
I like it when the new shows incorporate regular naval or military practice even though many fans, unfamiliar with military service, take unnecessary exception. (This goes for negative fan reactions to Ortegas behaving exactly like many combat pilots in real life.)