Star Wars vs Warhammer 40,000
Connection:
Both are massive armies consisting of human soldiers that served a galaxy-spanning empire (Galactic Empire and Imperium of Man respectively)
Both have multiple divisions within their ranks (Stormtroopers has the 501st Legion, Shock Troopers, Scout Troopers, Dark Troopers and Storm Commandos, while the Imperial Guards of Death Korps of Krieg, Astra Militarum, Tempestus Scions, Kasrkin, and Cadian Shock Troops)
Both also have a planet destroying weapon (Death Star for the Stormtroopers and The Eclipse for the Guards)
Both are also renowned for their famous memes and jokes (Stormtroopers are known to have terrible aim with their blasters while Imperial Guards are known to have died in any battle they've been deployed in)
