whats with all this "who is better in a 1v1 situation if they have the same gear" nowadays? There is no straightup answer for this; if you want to play whatever built wins I`d say you should better look at each of the built`s characteristics and go with the one which seems to fit your style best.
Depends who's playing the Guard and who's playing the Defender. When it comes to Guardians and Defenders the fight is pretty even. In my opinion Guardian is harder to play than Defender is so unless the Guardian knows what he's doing then the Defender will most likely win. But a Guardian that knows what he/she is doing would win.
I think the question you really wanted to ask was "What is best for me?" I would say go Defender because it is easier to play and usually people asking these questions are noobs and everyone knows noob Guardians fail. Just go Defender, it's easier, Guard is most likely too complex for you.
Pre upgreaded i'd go for hybrid guard now defenders are to tanky with all that dd from upreaded. This high hp makes 1v1 so lame and defedner don't need to build dmg
thats way easier combo for defender.