These races are much tougher to classify than in triathlon. Sprint events for one can be super short with as little as 4 miles total distance, or as much as 15 miles total distance. It actually usually depends on the distances of the main event next to it. They sprint distances actually rarely stand alone events, and are usually part of a bigger race. A way for race directors to let athletes get a "sample" of it without fully committing.
In Europe there are many races that are longer, ranging from 30km of running to 65km of running, and 4km of swimming to 10km of swimming, and all OTILLO races now have a shorter sprint event with them. But even the OTILLO races vary greatly, some suiting a more agile mountain goat, and others are more accomplished open water fish. Unlike in triathlon where a specific distance Olympic, Half or Full IM is "forced onto the land" in SwimRun the location is sought out, and the location then determines the distance. Whatever they may be.
The SwimRunShop.com has a very thorough event calendar https://swimrunshop.com/race-calendar/