1) When shooting at a Large Target, any number of models in the unit may fire, regardless of ranks.
2) When shooting from an elevated position, two ranks may fire, even though the back rank can't normally see the target. Likewise, they can see over intervening units that are lower than them.
3) When shooting at an elevated target, units can see over other units.
I'd say the argument is sound. If you're on a hill with Long Rifles (for example), then you could pick off a Damsel. (The truly evil thing about this example is that she won't be getting a "Look out, Sir!" roll...

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