I use both dry. I rarely use mixing medium b/c I'm lazy. I would personally say that the two can be used together on the eye, but i don't think that they are similar. Provence seems much more yellow and blonde's gold has a bigger punch of gold in it. In the pots they are noticeably different. When you swatch them, provence comes off lighter and a bit brighter, whereas blondes gold is a beautiful gold with just a hint of peach in it on my skin. I love them both and think they are both a necessity!
Honestly, the consistency of the two seem the same to me. Neither is really chalky.
HTH!