Artur,
The game is great and we haven't yet understand its full potentials...
Try this:
1.Action:
Add rough terrain on a hex. Then on top of it add forest.
Result:
Your armor won't be able to travel with more than 1-2 speed inside the forest.
2. Action:
Add impassable terrain on a hex. Then on top of it add forest.
Result:
Your armor won't be able to enter the forest hex.
Concerning smoke, in modern battlefields, smoke is not an issue of great importance
In post WW2 battlefields it could be an issue, but I don't think that to throw several smoke grenades would require more than 30-45 seconds?
cheers,
Pyros
p.s How about consuming two or three actions (shots) for using a smoke grenade? Would this simulate better the required time for creating an effective field of smoke cover? (don't get any ideas, I am joking
)