I don't think they are too similiar - #1 is more casual and #2 is more dressy/going out. I say keep both, but if you absolutely can't - keep the Guess ones.
#1 is great for weekends, casual outfits. Love the wedge. Great for denim skirts, bermuda shorts (dressy or casual ones), skirts, etc. i feel like this pair is more versatile than the second pair. I see these as teh perfect shoe option for work or play outfits.
#2 is perfect for work but might be too dressy to sport on the weekends, imo!