Re Lufthansa..
The load factor in August was 66%. However LH are soon to restart using their own metal on the route.They are dropping it from a BMI 320 back to their own B733/735/319 so a disappointing cut in capacity.
However it should insure increased load factor and at very busy times they usually upgrade to larger planes where necessary.
AFAIK LH look at the short haul schedules and bookings a few days in advance to determine which types should be used on which flights to best accommodate the demand - a very useful and efficient way of using the fleet. They have been doing this for some years.