Countering Fortune heavy Eldar
So recently, an Eldar player has entered my gaming group. I personally haven't played against him yet, but I did recently witness a 2000 point game between Eldar and Dark Angels. From what I noticed, the Eldar player had the upper hand, as he was casting Fortune about 3 times a turn has he had Eldrad an another Farseer, primarily onto Wraithguard, Harliquins in cover with a Shadowseer (so 2+ re-rolling cover) and Pathfinders in cover (again, 2+ re-rolling cover).
So personally, I am a bit concerned as even though Eldar is mostly T3, he gets to re-roll the saves of his most threatening units, many of which tend to be boosted cover saves. I feel that even with quantity of shots, it will be very rough to kill these units.
I realize that close combat negates the cover saves, but since I mostly play Necrons, I feel Harliquins would outperform me in CC in most instances.
So in short, what is the best way to deal with this kind of Eldar force?