And some more general info about trollkin:
Civilizational dangers of trollkin are not to be underestimated. Their bodies contain inactive mothercelium roots and enough of them in one place can actually start new nest. They are very resourceful, always taking over enemy equipment, learning new tactics and finding ways of destruction. They are restless in their efforts, and since their growth is fast and plenty, they tend to win over their enemies with numbers and morale alike during prolonged wars.
Grandest weakness of all trollkin is heat and fire. Troll's famous regeneration stalls when treated with fire, trollkin bodies no longer can spread mothercelium once burned. It looks like their numbers also grow slower in hotter climates. Another thing is infighting - it seems as different lines of trollkin - supposedly coming from different motherceliums - do not work like united species and more like different nations. We can only guess it's a matter of time until some of them develop heat resistance.