Brink will differ in this aspect for a few reasons:
Although this is a good tactic, it won't always be successful and here's why:
In both QW and ET, grenades can blow up enemy mines, whether they were detected or not. So when people start playing Brink and they are learning the game, the maps, the tactics, etc. mines will be sick. A lot of players won't be expecting them and some won't even know they're in the game. But eventually, when players start to get their [censored] together, they are going to learn where the Engineer "hot spots" are for planting mines, and like clockwork, they will come to these areas and instinctively toss nades as a precaution. Now this doesn't mean mines will be useless - there will always be an abundance of idiots who get killed by obvious mines - but as more people play and learn the ropes, the more clever Engineers will need to get with their mines.
Of course, Brink could be totally different, and nades can't blow up mines or whatever. I'm just basing it off gameplay tactics I remember doing and seeing when I played ET and QW.
Any game that has mines, grenades, turrets etc will always have good spots that the experts know about while newbs dont, Learning the tricks is part of the game and the learning experience. However once the spots are known new spots are made and the learning curve starts over again.