Some planets lack any non-restricted terrain. For example, Hoth only has glacier and mountain terrain. Given that facilities only up to 5x5 can be built on such terrain, and a shield projector is a 7x7 facility, does this mean that it is impossible to set up any planetary shields on such planets?
Shield generators create planetary shields. I'm assuming that he had a brain fart (because I know he's built plenty of shield generators) and for some reason thought you needed a shield projector to have planetary shields. To answer your question, no, you do not need to have both, you need only a shield generator. Shield projectors are not currently coded, but as far as I know they will work like the Endor shield generator, boosting the shield levels of a space station or something similar in orbit.