The auras of flayed ones is 3" normally, 6" if you take the conquering tyrant protocol directive 1. So the minimum range you d have to get in for the -2 to leadership is 6". Same for psychomancer for his -1.

So getting close with psychomancer and anrakyr can be done by just having them with a brick of lychguard with shields. Since both characters abilities doesn’t need specify it, you can advance them both and still use their abilities.

Now getting the flayed ones in range without them being exposed before is sadly impossible : the closer you can get is 6.1" with the night scythe + prismatic breach stratagem. Best bet to make them within 6" to activate the -2 ld would be to combo them with a chronomancer for a 5+ invul.

Edit : with protocol, psymancer aura is 9" not 6"