A good rule in proper speaker design is the tweeter above the midrange, midrange above the bass driver. Its where the drivers combine (at crossover points) that the dispersion of the speaker is determined.
Some designers routinely mount the tweeter below the woofer to better time align the drivers which also results in a simpler crossover network. I think its a much more novel and effective way of doing so sonically, eliminating extra crossover components and the only real consideration is proper placement. There is also consideration given the subject of lobing that is rarely brought up in these posts involves the relationships between the upper and lower frequency drivers on the front baffle, the cross over network along with the listener’s listening position relative to the speaker system as a whole. The designer has taken that into consideration throughout the design process.
Oh, and always having your tweeter at ear level is not always the best thing unless the designers actually intended it to be that way which most of the time they don’t.

