Coming back to this old thread because I have taken a screenshot which shows how strong the Scyther is when used with a specific setup (Assault / Infiltrator with Vengeance Torso) and also to get an impression of its AoE effect in an arc up to 3 tiles distance:
This is a triple kill with 1 AP usage, the Close quarters specialist perk isn’t really needed, it deals 600 damage without this perk thanks to Sneak Attack, enough to kill all the foes. And even when SA should be nerfed, in this situation it would be 2 attacks to kill all three enemies, 2 AP spend and all AP back because of Rapid Clearance.
My Terminator build No. 1, IMO beats anything that is also possible and no personal perk is really necessary.
The one in the screenshot has additionally anything that makes this even stronger, CQS, Quarterback and Thief, so full stealth and with high speed (base 24, with Frenzy 36).