Best way to move lots of characters

Hello.

I need to move lots of AI characters. Around 200 or more if possible. Right now I`m using:

UAIBlueprintHelperLibrary::SimpleMoveToActor(GetController(), GoalToMove);

Now, I have few questions and hopefully someone could help me to chose which way to go.

-Right now I have around 70 characters that when get spawned, they call that function above. But here is the weird thing: the World Tick stat is higher than when all those actors are not present in the scene. I`m disabling the tick with:

PrimaryActorTick.bCanEverTick = false;
this->SetActorTickEnabled(false);

Which takes me to the first question:

**>Why is the World Tick so high, even with those actors having tick disabled?

Could it be because the SimpleMoveToActor is called every tick in a global Tick call?**

And my last question. I need to move a lot of characters around with simple AI:
-Go to point.
-If close to certain actor, attack.

**>Base on this, which could be the most cost effective way to do this?

Do the functions in C++ and play with overlaps, not using tick in these moving actors?
Use the AI system from unreal engine with blackboards?**

Thanks.