Relative strength is the size of the levy (total or current) as a percentage of the top liege. So it's always 100% for the top guy. It's usually not the case for his vassals. And if it is...he's in for some trouble =D

Your assumptions on total and current are correct.

As for relative strength, it is the size of the levy (total or current) as a percentage of the top liege. So it's always 100% for the top guy. It's usually not the case for his vassals. And if it is...he's in for some trouble =D