In this position paper we focus on students who are contracted to fulfil teaching roles. While an accepted practice, student teaching assistants (STAs) tend to lack teaching experience as well as having only limited subject and pedagogical knowledge. As such, there is a trade-off between employing them and maintaining quality in teaching. We identify assessment feedback and grading as particularly important aspects of teaching that are often beyond the capability of many STAs. Rather than suggesting that students should not teach, we provide a nuanced examination of who these students are and argue that assessment and grading should only be entrusted to STAs who can do these tasks to a satisfactory level. Ultimately, we call for a critical discussion on the merits of employing students as teaching assistants, taking into account the diversity within this group and within a teacher's roles.