It can be eady to confuse reference stuffing (using as many references as possible for the sake of looking smart) with the appropiate use of multiple sources. An example:
"Source A says xyz about the essay subject, which is contradicted by Source B. If the papers by Source C and D are considered, Source B's conclusion is the most likely in the context of the current question." (Continue by explaining why, potentially drawing in more sources)
4 references in 2 sentences/38 words. All references are appropriate to the essay question, demonstrating critical analysis and an understanding of the sources used. Allowing about two hundred and fifty words each for the Intro and Conclusion, that easily leaves room for 30+ entirely appropriate sources if you read widely enough and have the capacity to assimilate and correctly use the resulting breadth/depth of information.
A large number of references cannot be automatically assumed to indicate a lack of knowledge or critical/analytical capacity. Bear in mind also that there may be distinct differences between styles of work for Humanities and STEM subjects, where the latter tends to prefer much more concise written work. I was always encouraged by lecturers to read as widely as possible around coursework and to demonstrate that reading/understanding through the appropriate use of sources. All I can say is that it worked well for me (BA & MA).
Of course the Gold Standard reply is that, when in doubt, you should ask the person who has set the assignment as you work.