I think the order and placement of the words is also important. The format "(noun) shelter" is similar to and might more readily bring to mind "animal shelter"

I think the order and placement of the words is also important. The format "(noun) shelter" is similar to and might more readily bring to mind "animal shelter" and "homeless shelter" than a phrase in the "(verb) shelter" and "shelter _____" formats. The mind is very pattern-happy after all :)