While researching this I couldn't really find any information of the main design architect or the group of builders that built the shrine in 780 when first built or in 1633 when it was decided by Iemitsu to be rebuilt. I was just curious if there was any concrete information out their about the designer or the construction crew who first built it during it'd lifetime.
I think i found some information about this myself. From this text http://www.khamkoo.com/uploads/9/0/0/4/9004485/faith_and_power_in_japanese_buddhist_art_1600-2005.pdf on page 37 it says the Tokugawa Shoguns were part of the construction process of the the large scale temple projects during their tenure. They are directly related to the third shogun Iemitsu who ordered the reconstruction of th temple in 1633.