[thmsths]

I don't know if one trajectory is more efficient than the other, but space propulsion systems are quite tricky and if I remember correctly the X prize was trying to incentivize doing things on a budget to "democratize" access to the moon. It was basically the cubesat of moon rovers. If you think of technical decisions through that lens, it therefore makes sense to ask your launch provider to do as much of the work as possible since they already have a second stage capable of getting you there, instead of designing a bigger payload with a more capable propulsion.