Ian Jackson explained :
As I've said, there are times when it is lot better if drivers merge early,
and try to maintain the maximum possible safe/legal speed.

I disagree, an orderly merge done with good cooperation at the actual
pinch point maximises the road capacity, whilst still getting the
maximum number of vehicles through. No one can easily take advantage,
if both lanes are fully occupied to around the same level, the merge
flows smoothly, everyone gets there proper turn, no timid drivers are
disadvantaged.