Quoted for truth, just double checked ingame. 3 Buildings go down to 8 mines, another point on my wishlist : damage modifiers against everything so that every weapon does different damage against buildings, infantry and tanks.
hmm well maybe the mines are bugged agian.. because i use to do what you are talking about here but then after the mines got changed i tried it and it only would damage the buildings and not kill them(maybe this changed with the damage upgrape for them awhile back)
9 mines takes a long time to set up... not much a grenadier can do to defend himself during that time. see I see mines as a satchel charge too, and the loooong long set up time and time it takes to get into a base, and grenadiers are relatively slow and easy to kill once spotted. frankly i think they are an interesting tactic that adds to the gameplay. I just think it's so easy to counter, and as tactics go it's very slow, taking you away from your team for so long, that I think it's more fun to include it in the game.