I'm not sure what you're getting at exactly but it is well known that Blizzard's titles were directly inspired by the Warhammer and Warhammer 40k universes.
While the visual similarities haven't causes Games Workshop to complain about infringement from Blizzard (as far as I know) it doesn't mean that Games Workshop isn't complaining about infringement in this or other cases.
Clones are part and parcel of the gaming world, but folks still need to change their IP.
From the look of the UI, it even has a time countdown slider for each turn, something fairly unique to Space Hulk. I kinda miss that, it really made Space Hulk tense. Still, it's a 20-year-old game, probably time for a remake somewhere :)