Earthshatter potential bug?

wanna keep it quick and simple:

MY earthshatter 10% has: maximum 7 spikes

support with upheaval to create 3 spikes at once

possible bug: i can cast 7x earthshatter with enough atckspeed to get 21 spikes, and can also explode them with any warcry for the 21xdmg if the target is big enough, sounds like a bug to me, but i am not sure

Was going make a similar post.

No quality earthshatter + upheavel + 3 warrior totems bonking twices gives me 18 spikes.

I was wondering if the spike limit was per entity i.e. 6 spikes per totem.

(But I do think Earthshatter either needs bigger AOE or more maximum spikes if the above wasn't intended)