The only way I found to hunt these without going completely insane is to have 'select next target' on screen or hot keyed (have 'move to target' checked in options also.) Even then they are still the most painful mob I've found to hunt.
Completed Stage 3 last night. Loot: They also drop Headshot I (L) Mission reward: Swordsman (Dmg) went from 42.1206 to 42.1530 I don't know how to calculate the chipsize. Question: Do they also have a repeatable mission?
Estimating your starting skill at 3346.6 and finish skill at 3392.9 then Entropedia http://www.entropedia.info/SkillCalc.aspx reckons that's a TT value of 1.54 ped.
Completed Stage 4 last week. Using that tool on Entropedia, I calculated a Longblades-reward of 7.59 PED. Neat!