I would have thought, if that were the case, that you would more likely end up with something like the temples of Malta rather than something that really does resemble a large, formidable fortification. The walls of the temples on Malta are gigantic and certainly meant to be imposing but the use of space inside is the priority.

Some of the internal structures also seem to have defensive features, entranceways that confuse and put intruders at a disadvantage and pits that could be concealed. Structure 10 even looks like it had guard posts recessed on either side of the entrance, with a passageway leading around the back of the building.