This is an unusual print configuration in several respects, particularly in that the numbered items appear to be source information about the exercise item. In a case like this, I suggest establishing a format that is consistent and based on the guidelines and the reader will see that pattern.
The issue is not that the indentions are the same, but that the RUNOVERS are the same based on the number of levels. In the Louisa May Alcott situation I see a series of displayed paragraphs all on the same level. I think it best to keep this simple and since I personally read these paragraphs as being on the same level, the runovers and indentions will be the same. In this way, there are only two levels, the numbered and lettered items. The numbered item is 1-5 and the letter item is 3-5.
I like 10.7 for this. It deals with the displayed paragraphs in item 5 and the displayed poetry in item 6. The actual directions are blocked in cell 5 and the displayed paragraphs are in 7-5 with a blank line in between them. See Examples 10-3 and 10-4.