Zero Friction Cycling found that Shimano parts are softer than SRAmM. Shimano chains last better with Shimano cassettes, and Sram with SRAM. The say SRAM chains will wear Shimano cassettes.
Some of the factory Ebikes have gone to drivers as small as 9 teeth. I run a 50t ring and spend most of my time in 15t, maybe 13t if I'm in a hurry. rarely the 11t top cog. I haven't had excessive wear or breakage. I do rivet my chain because I've broken a few of the tool less links. I've gone to Front Freewheel to keep the chain moving when shifting where pedaling isn't possible. That helped a lot. But the Sunrace 11-40t has worked well for me, and no problems os far with similar Shimano. But maybe it will wear faster over time?