So this is something I tried out once or twice in 4th Ed and totally forgot about until after seeing a poll on Awaking Ynnead.
While I typically use my Farseer to boost shooting power there's no reason they can't up combat ability too. As long as you're not running into squads full of power weapons a quick roll of Fortune before the combat is going to turn Striking Scorpions into some pretty resiliant dudes. If my math-hammer is correct somewhere near 90% chance to pass saves, which even on the toughness of an Eldar is going to make a solid unit. Add into that Doom and they'll be cutting a pretty clean path through for little damage in return.
So though I previously said I was going to drop the Scorpions from my list I may rethink that. Besides which, Scorpions are obviously the coolest Aspect out there!