As always, the 13-inch only has one fan, and 15-inch has two.
[https://appleinsider.com/articles/19/07/15/tested-thermal-throttling-in-base-model-mid-2019-13-inch-macbook-pro|https://appleinsider.com/articles/19/07/15/tested-thermal-throttling-in-base-model-mid-2019-13-inch-macbook-pro]
[https://www.digitaltrends.com/laptop-reviews/macbook-pro-15-2019-review/|https://www.digitaltrends.com/laptop-reviews/macbook-pro-15-2019-review/]