Some light googling seems to indicate that in German (my native language) the adjective order doesn’t really matter, but some say it actually does (citing pretty much exactly the same rules as in the linked article).
To my ears „grüner, großer Drachen“ doesn’t sound as correct as „großer, grüner Drachen“, but maybe that’s just my knowledge of English leaking into my German. It doesn’t sound entirely incorrect to me, either, not in the same way “green great dragon” does. Maybe German does have the same rules about adjective order, but they aren’t as strong? Maybe a teacher would put a wiggly line under wrongly ordered adjectives, but it wouldn’t actually be a serious mistake, just a weird stylistic choice?
Also, it’s entirely possible I actually was taught about adjective order, but have forgotten all about it. If you learn English for nine years (with either four or five lessons per week) you do lots of reading and writing, especially during the later years, actual texts from the real world and actual essays. It‘s very possible I picked it up through that and it was never necessary to explicitly teach me about adjective order.