Supose you are a High level Wizard with acess to both Simulacrum and Magic jar. There are a lot of discussion if the simulacrum has or no a soul,and if that interfers in the use of magic jar,since the spell expecificly discribes the trasportation of the soul. The spells says:
Your body falls into a catatonic state as your soul leaves it and enters the container you used for the spell’s material component. While your soul inhabits the container, you are aware of your surroundings as if you were in the container’s space. You can’t move or use reactions. The only action you can take is to project your soul up to 100 feet out of the container, either returning to your living body (and ending the spell) or attempting to possess a humanoids body.
That means that it does not describe the need of you to be a humanoid to cast
So, There is anything in the raw that prevents the simulacrum from casting magic jar except for lore purpuses?