Welcome to the Strelets Forum.
Please feel free to discuss any aspect of 1/72 scale plastic figures, not simply Strelets.
If you have any questions about our products then we will answer them here.
Your point was:
"...as far as I know trousers have never been issued to German regiments."
Well, clearly, whether for drill only or not, they were issued (at least for the Nr. 3 Erzherzog Carl Regiment). The evidence is there. Of course, you are free to ignore it.
Have a nice day.