It took me a while to spot them too. For anyone else about to play the game
I figured out the right order by looking at the names mentioned in the book, the first name starts with a C and the second name starts with an S. I have no idea if you made this intentional or not, but that's one way to communicate the ingredient in a non-obvious way.
As for other ideas, perhaps word puzzles? Something to decipher, fun but not too difficult? Consider the other potion book you added where the words are faded and incomplete so the reader has to deduce the ingredient from the letters that are left.
You shouldn't worry about that for now, I think the bookshelf is a bigger priority right now because soon enough there won't be space left on it.
Perhaps it's better to leave it that way, yeah.