I recently flew to Berlin on LH on a Z fare. I admit being shocked at the baggage policy.
I usually carry a normal piece of rolling luggage and then a second bag. I had packed some camera lenses in my roller. Just assumed baggage policy would be the same as United's - 2 bags onboard. Not only do they only allow you to bring one only (unless you are in business or first) the size limits probably shouldn't have permitted me to bring the roller on board.
I would have been completely hosed if I wasn't flying business...and even then, I am guessing they could have told me to check my roller since it was technically to large.
If this was in the hold, I'm not sure my camera equipment would have survived.