I used to think that if you saw 5 grouse you should only shot 2 or 3 too. But a few years ago there was an article in one of the hunting mags about grouse conservation. A biologist said something like "Grouse populations in BC go up and down in cycles, and hunting by humans doesn't really change that. The limiting factors will be the point in the cycle, habitat, predators and weather. So shoot away"
And then we get to the very real question of how many should you shoot?
If you see one, do you shoot it? Or do yo assume someone else shot the other 4 and leave it alone?
If you see two, do you shoot both, assuming that there are still some unseen in the bushes?
If there are four, and you shoot 2, then someone else comes by the next day and shoots the other 2, should you have shot all 4 anyway?
If there are 3, and you shoot one, but a coyote gets the other 2, should you have taken all 3, since they are all dead, and now the predator got an extra meal?
And possibly the most important question- how many grouse do you shoot a year? If you are limiting out 5 days a week, you are going to have a much bigger effect on grouse numbers than the guy that shoots 4 out of 5 grouse, once during hunting season. So there isn't really a cut and dry answer, other than it's legal to shoot 5 grouse at once in BC.