rene&diana tank vs nas?

so here is an image of their champion stats in terms of who can have the most defense

http://s70.photobucket.com/user/neopets_acc/media/2017-02-20%202.png.html?sort=3&o=4

here are the site i used http://leagueoflegends.wikia.com/wiki/Sona http://leagueoflegends.wikia.com/wiki/nasus http://leagueoflegends.wikia.com/wiki/renekton http://leagueoflegends.wikia.com/wiki/diana

rene build http://s70.photobucket.com/user/neopets_acc/media/2017-02-20%209.png.html diana build http://s70.photobucket.com/user/neopets_acc/media/2017-02-20%2010.png.html nas build http://s70.photobucket.com/user/neopets_acc/media/2017-02-20%208.png.html sona build http://s70.photobucket.com/user/neopets_acc/media/2017-02-20%207.png.html

so i was playing the sona and i made these posts to show you guys the builds and why it really doesnt make sense why we lost when diana can tank more than nas.... we have two tanks and they only have one i also have a lot of magic pen and ap items but i couldnt do dmg....? isnt lethality a dmg item?