I don't believe that differences in stroke can make any difference with regard to the need for glow plugs or not.

Furthermore, the determination of the need for glow plugs is heavily dependent on the application. Put a diesel in a pickup truck and the driver expects it to start in a similar fashion to a gasser.........no long cranking. So, glow plugs are a necessity. I don't know of any light duty vehicles without them.

Put a HD diesel in a truck or a ship and the expectations are completely different. These fellows will crank them for a couple of minutes, if necessary. They'll haul out the can of ether, if required. They'll run the engine all night. Doesn't really bother them. Hence, the manufacturers eliminate the glow plugs from these engines to save money. There is no doubt that they would benefit from glow plugs in cold temperatures.