To move towards a longer drill may be one reason, yes and/or to work on specific parts of someone’s training may be another. Not sure I would use them in an unloading week (they can be quite stressful) and/or much later in the season (you need to put it altogether at some point). It’s always a combination of intensity and volume anyway, of course. Others?
PS by “…100% for SE” do you mean effort-wise?