You’re conflating the length of a word with the volume of words. In Orwell’s five (or six) rules, he is not at all arguing we should limit our vocabularies and only choose from a select number of options. In other words, he is not saying we should banish words like violet, purple, azure, indigo, cobalt, teal and only use the word blue instead. This is a total bastardization of Orwell’s point. He was, however, pointing to the dangers of this notion in 1984. There is no conflict here.