Simple suggestion: building health should be increased. Explenation(spelling?): ninjaing is generally fine, but i think one grenadier being able to take out a building without being detected before it's too late is just not fair play. If you let 2 or more grenadiers get in to your base then that is good teamwork on their side and they deserve rewards for doing so, but one lone wolf being able to annihilate a building shouldn't happen in a team based game. Mine damage is fine (maybe even slightly underpowered, but that's not what we are discussing here) and instead of rendering mines unuseable simply increase the health of buildings.
If you let even one grenadier into your base undetected you're doing something wrong. They aren't built for stealth or infantry combat, two things you need in order to infiltrate a base. Simply placing MG turrets at crossroads in your base will keep them out. Making buildings more resistant to certain weapons would be concieveable, but not grenadier mines.
Building health *might* be increased but most of it is fixed by removing 9th mine trick (1st mine won't detonate).
The ninja problem doesn't seem all that bad. After all, the grenadier can only take out one building unless he brought an engineer/apc with him. It shouldn't be hard to rebuild it. That said, if you expanded the idea, you could use it to solve/improve on several other problems in the game besides 9mining. Complicated Suggestion: Increase Building Health of Barracks, VF, Radar, and Refinery Increase Engineer's (and possibly other infantry's) base build speed, equivalent to repair upgrade. Decrease Engineer's base repair speed. Repair upgrade applies only to repairs. * Build speed is when structure is yellow/unbuilt. Repair speed is when structure is green/built. It would change the base-defense dynamic... Your bigger buildings would survive longer, so defending your base would become an option, instead of having to hide inside and repair it. The changes would also affect the construction of buildings, and the One-Skill-Wonder that is Repair Upgrade. Admittedly, you'd only be able to 9-mine armories. Would it be awkward to ask for a damage bonus to buildings, or would it just be better to pump in a few mortars afterwards?
Actually, well placed mines can take out multiple buildings. From personal experience, there was a match on emp_canyone, I was on NF, I was a grenadier carrying 10 mines, and was in enemy base. The radar was directly infront of the BE barracks, the the VF against the broadside. I put my mines right in the middle, and took out all 3 buildings. You could probably do 4 or 5 if the base was arranged in such a way.
Would take away lot of the thrill being a grenadier... and it takes long enough to lay 8 mines to kill the grenadier.
It'd be much better just to reduce the damage done to buildings by mines. I don't think it should be done, just that it would be the better suggestion.