There were segments of the lorica segmentata found at the areas where the battle took place, so it is reasonable that they were used (in small numbers) in the battle at teutoburg forest. That´s why I use mostly conversions of the roman infantry made by Italeri with the lorica hamata (mail armour) and only small numbers of the Zvezda imperial romans. But I think that an Optio as an officer may have had the lorica segmentata. The problem is to find good-looking german warriors. The Caesar Miniature Germans, that I use, are nice but the poses are not very usable for me, so I can´t use a lot of them.
For me it is very important to show many different styles of roman equipment, because there were lots of variations at the same time.