These things are stronger than the 15 and 20 mote enemies by far.
The constant teleports and taken spheres just give them so much survivability and control.
There's no reason to go over 5 or 10 motes now. A cheeky fiver here and there to give invis to Primevals and Captains and if not 5 then just spam 10.
There was nothing wrong with the Phalanxes before, maybe create a whole new 20 mote Taken Captain with a scorch cannon and give us back the Architechts.