Look mate, I get you're worried, but have some facts. Guns don't have the range of bows in WHFB, but they do have quite a bit of range. Since we have time to line up a shot, and have a reasonably good dwarven gun, so our effective range is something like 20-80m, for a human sized target. A headshot is probaby hard at that distance, but again, all the time in the world to aim the shot and make it count, as well as being able to brace the weapon. Take no Heed is used on approach, if needed, and after switching our mien with Doppelganger to escape. Again, if that turns out to be the way to get gone, rather then just becoming an invisible shadow, and fucking off.
It's not meant to hide us while we are firing, that's an entirely different spell, one we don't know.
The targets are well illuminated, and over a pit, so we have long, clear firing lanes, and warrens to escape to after shooting. It's risky, but if the Goblin is a Leader, and it seems to be, based on warpstone and armor, then that's a big deal. Goblins losing a leader are even worse than orcs losing one, especially with an army pressing on them.
It is risky, but it is exaclly the kind of risk Mathilde is built to take. That doesn't mean it will work, or we get out for sure. We could die here. But that is true in any battle. It's a calculated risk, a decent risk, for good rewards.