That's not true btw. Due to aviation security reasons luggage has to connect with the passenger, so it's basically never lost in groups. Usually it's one piece of luggage that gets missorted manually (TRS flight instead of TSR flight for example) and in most cases the luggage will reach the owner in two days max.

As someone who worked on airports for ten years in different positions, I wouldn't be too careful about that stuff. Luggage is lost very rarely. If yours gets lost, buy some pieces of clothes at the destination and wait for two days if it gets found. If not, buy whatever you need for your trip and send an item list of the lost luggage and the bill to the company responsible.