How much sweeter than almond paste is marzipan?

I have to substitute marzipan for almond paste in a recipe because there is no way for me to either buy or make almond paste. The almond paste would have been mixed with 1/2 cup of packed brown sugar and the same amount of softened butter. I know it'll be far too sweet if I use the same amount of sugar, but having never actually had almond paste, I don't know how sweet it should be. Does anyone know?

This is for a kringle (pastry) filling, if it makes a difference.

Thank you.