Dominique please vote for 600m
That's what I've just done.
In fact, it's the name "Haie-Sainte" that bothered me.
If thant means the "Haie-Sainte rigde", even if it's not really a ridge and nobody ever used that name, that is surely closer to reality.
The reason why so many people put the Grande Batterie so far to the back, is that the 6th Regt Artillery was placed there around 11.30 , but it was moved forward around 1200 - 1.00 pm.
So many maps, showing the positions at the beginning of the battle, show the artillery at that position (just NE of Belle Alliance).