When you plant bookcases near an enchanting table, it increases its power because of magics. What does this actually mean when I go to enchant items? If I have more bookcases will my enchantments, other things equal, be better, or does it just raise the limit on possible enchantments?
And more nitpicky, what about the "between" cases: There are overlapping ranges where you can get (for example) Sharpness II and III (lets pretend 15-18). If the presented enchantments were between 15 and 18 levels, would it be impossible to get III without X bookcases?