It works for what it is supposed to do: be a mental “book” that you can use to check on information when you can’t immediately recall it.
Ordering it alphabetically is fine, but you have to remember that it does not mean that you know it in a way that you can grab it from your memory instantly. All that you have is a mental note of something you want to remember.
Frequent reviews of your palaces help, but you mentioned that you would need 20 giant memory palaces, meaning that you probably want to remember a lot of words, so I don’t think recall alone will cut it.
Now, maybe there are some better advices from people who memorize languages more than I do, but I’d say that your number 1 focus should be on using the words. If you use them, you have less of a need for your memory palace. This should help a lot already. You can then also use your loci for the words you really have to memorize to know.
Especially if your goal is conversations or other fluent use of the language, memory palaces alone are not going to get you there. Using a language is like riding a bike, even if you know all about it, you will still fall on your face if you never do it.