I just got a follower mission that required 2 technician counters…
There is only one technician follower per faction. This mission is impossible to counter. So my question as an OCD perfectionist is:
WHY MUST YOU HURT ME LIKE THIS BLIZZ?!?!?!?
https: // imgur . com / a / kherPDP
As far as I know there’s no way to counter stealth, so there’s that as well.
Didn’t the last patch add a follower equipment item that counters stealth so you can send the low level minions along?
/moo 
Found it - 
Vial of Obfuscation
In the last two expansions these things were built into the mission board. The Vial has to be crafted.
I like the “Requires stompy noisy troops to counter the abilities, but DON’T BRING STOMPY NOISY TROOPS IT’S A STEALTH MISSION -100% FOR YOU” conundrum.
Vial of Obfuscation, which is made my alchemists, counters stealth missions.