Walking over open ground under enemy fire is something no player would ever think about in ASL. Especially if MG is present. Assault movement is standard form to make slow and protected progress over open ground, backed up by use of smoke it is even relatively safe.
In ASL, smoke gives partial cover (hindrance), but does not protect entirely. In Landships we may assume troops using assault move as standard form of movement and it makes no difference for defensive fire if footmen have been laying low for the turn or walked across the field - at least not until IM is introduced. In L! smoke makes footman immune to fire in a sense that footman may walk across no mans land without fear of being shot to pieces. As it may be difficult to see the unit on smoke, it is far from impossible especially on close quarters if opponent is moving.
How about close combat in smoke? Is it more difficult for attacker to find the defender? Does defender receive an advantage over attacker as their position is not clearly revealed? Defender is hardly surprised if concentration of smoke follows by assault.
IM brings forth idea of moving troops being easier to spot and hence they are more likely to get shot. By those means, smoke should give bonus to hide under but should not affect fire in any way if troops are spotted.