Agro mobs shouldn't be summonable I suppose, usually they are not.
Below log represents certain matchup when you can instantly kill any duergar as soon as you've got summon spell/commune. Let's see if it's working as intendet or shouldn't be like that.

Log:

Someone has summoned you!

A dangerous dwarf dressed in ornate armor guards his post without regard to life.

The elite dwarven guard yells 'Only cowards run from battle! Stand yer ground and die with courage!'

*SNIP SOME*

And I'm going to be not as polite since you were dramatic/misleading purposefully in your post.

That isn't an aggressive mob.

See the yell it did?
That means that mob was already chasing you. It doesn't yell that unless it is already chasing you.

So maybe next time provide the correct context showing a mob is aggressive instead of misrepresenting what happened?

Sorry for bothering you, I'll ensure there will be no next time.