In the traditional "Maneuver Army" a "doctrinal task" for a maneuver unit is something that must be done, and it must be paired with a "doctrinal purpose" to be a complete mission statement.
"A Co will attack to destroy the enemy in Engagement Area Zulu"
"B Co will conduct an area defense to deny the enemy access to the fastest route to Objective Wrench"
"C Co will conduct a raid to disrupt enemy logistics in Sector 5"
In the Maneuver world, where we are moving men and
equipment around the battlefield, the end state is defined with regards
to enemy, friendly, civilian, and terrain. Such as:
end state A Co has secured Hill 118 and positioned to conduct follow on
operations, denied the enemy advance along Axis Tubman, and ensured the
town of Mainville south of Hill 118 is safe from enemy counter attack.
On the Fires and Effects side of the house, a doctrinal task and purpose is an "effect with regards to the targeted formation." Such as;
Task: Deny the enemy Commander access to frequencies 462 through 467 MHz to degrade command and control. The effect you want is "denial" in order to degrade C2. Of course you could write it the other way around, "degrade enemy C2 by denying the enemy free use of frequencies 462 through 467 MHz"
Task: Destroy the enemy tanks in Sector B to deny the enemy main effort reinforcements. The effect you want is "deny the enemy main effort reinforcements" and you are doing that by destroying tanks.
There is no "endstate" for a Fires/Effects task and purpose, there is a measure of performance (what we do) and measure of effectiveness (what happened to the enemy). Measure of Performance are easy to write, but measures of effectiveness are a tad trickier. Nowhere else on the battlefield does the enemy get such a large say in how you get rated at doing your job.
For our first fires mission, destroying enemy tanks to prevent reinforcements, we plan to allocate 22 rounds of heavy artillery to fire on grid square XYZABC. We fire the rounds (our measure of performance) but they failed to destroy the tanks (measure of effectiveness). However our artillery strike took out a bridge that stopped the tanks from reinforcing the main effort (yay, we succeeded in stopping the reinforcements!).
Alternately, we could have destroyed the tanks, but had no effect on the motorized infantry company the tanks were supporting and the enemy main effort was reinforced, so how do you measure success there? We fired 22 big rounds (Measure of Performance, what we did) and destroyed the enemy tanks (effect on enemy) but failed to prevent the enemy from reinforcing which was the whole purpose of the task.
I bring this up because this is the real heart of Counter Insurgency (COIN) doctrine. Yes there is a kinetic fight where "Company A will conduct a Cordon and Search of Village Goatanus to deny the enemy safe haven" but the larger fight is one of effects, such as "Company B will conduct stability and support operations in the Ramfuk Valley to gain popular support for the Coalition governance line of effort."
Never before in the history of warfare have Commanders at all levels been so concerned with "effects" of operations as opposed to the "movement and maneuver" portion of operations. After all, no one wants another "Mission Accomplished" moment where we say, "Yeah, we kicked their butts!" to then spend a decade trying to unscrew the pooch.
Now I might not be the smartest guy in the room, but I'm pretty sure what Mohomo Donkeylover insurgent commander is doing is effects based targeting in planning bad guy operations. They did it poorly in Iraq, but better in Afghanistan. In Afghanistan they are masters of the human terrain and understanding the effect that their operations will have on the local populace, whether they will build trust or tear down trust.
I apologize for all the back story, but the lesson learned is that if you don't have enough men and equipment to conduct traditional maneuver "Task/Purpose" for your operations, you should consider the "effect with regards to a formation (enemy or civilian)" tasks in planning operations. And even if you do have enough men and equipment to play chess on the real world battlefield, you should always understand what effects your actions will have. The road to hell is paved with good intentions, if you are like me and suck at predicting how people will react, bounce some ideas off your wife (or someone with better interpersonal skills).