If you are not at the expected Spanish speaking level per class instruction, they place you at another local school (I think Tubman is the choice but have not looked at this recently).
If I was in your shoes, I would try and land in bounds for Murch.
Lafayette is getting a new Principal next year- and it is a really big school. For a child in an ELS classroom, you may want a smaller school.
Important: If your child is going to be placed in a self-contained classroom, it is not 100% based on what is your neighborhood school. You can live in-bounds for Murch, but if there is not a spot for you, they will bus you to the next closest ELS school that has a spot. They try and keep you in the same "feeder plan" as your local neighborhood school - but this is not always the case.
Here is a link to the feeder patterns for special ed self-contained classrooms:
https://dcpsspecialed.wixsite.com/home/self-contained-feeder-patterns