I'm looking to make a French 16th century article of clothing/accessory. I can find German embroidery from the same time period, or French patterns from the 17th century, but not both.
Are either of these "better" than the other? Does art or fashion or style not change as fast as it does now, so the older, French motifs are a safer bet; or, is it more likely that art/fashion/style cross regions/borders?
Check a secondary source and then see where it gets its sources from. In this case, maybe a museum or a book with photos of the historic objects/styles.
We have a few history of dress flairs around the sub, so hopefully one of them will be able to help you out with some of the specifics of costuming in this period. In the meantime, I can try to help with what I would do, though my training is in scholarly art history and so is not totally analogous to the needs of historical reenacting or reproduction. If I were you I would do research on the history of dress in the sixteenth century in both France and Germany. What were the major influences on dress in those places at that time? Did they share a common influence (like the French court, perhaps)? If so, you might be on relatively firm ground if you chose to use the German pattern. If the Germans (which Germans will matter too, possibly) had a different set of influences than the French, then you might be on shakier ground and should instead try to find sources from whatever embroidery traditions influenced the French (like the Italians or Flemish, maybe?). And, of course, as an art historian I also suggest looking at contemporaneous paintings (especially portraits) and other visual sources from both places (especially France). What are the people in these paintings wearing? Do the clothes look the same, or different? Even if the paintings don't show embroidery patterns of the type you're interested in, you can get a sense of whether the clothes in general look the same.
As someone who is knowledgable about embroidery and other matters of the fabric you'll probably be better equipped than I to determine if, say, a portrait of Henry IV of France is wearing clothes that are more similar to one of his German contemporaries or one of his Bourbon descendants.
There was considerable artistic and cultural cross-pollination at the level of nobility and royalty in the sixteenth and seventeenth centuries, increasing as time wore on. Peter Paul Rubens, for example, spent time in Antwerp, Rome, and Paris at various points in his life. So it's definitely plausible to think that dress conventions were shared throughout these areas. To my own untrained eye the patterns you've shared look similar, for what that's worth (little, I suspect).
Anyway, I hope that's a start that can get you digging into the literature on the history of dress in the Renaissance and Baroque periods while you wait for a history of dress flair. Good luck!