Something more funny: this troll is stunned, but it is still moving.
Borresaine gives it a critical hit and stuns it, then borresaine and tanglefoot cooperate and give a AOE stunned, other two trolls get stunned, the first one gets stunned but starts to move.
Now we can see when tanglefoot attacks without Borresaine (the above one), it only causes hobbled. 3 attacks.
When tanglefoot cooperates with Borresaine (the bottom one), it causes hobbled and stunned. 6 attacks.
And not sure when the cooperated attack influences teammates. Sometimes allies get stunned, sometimes not.
Besides another test show that even though Borresaine doesn't give a critical hit, tanglefoot still stuns them all.
Image here:
http://images.akamai.steamusercontent.com/ugc/252591571772888834/513B5C8E211538D7C74B7EE73F948A70473B1C38/