The top statue doesn't look very bronze with me. The bottom looks almost coppery.
The question is: how much work do you wan to spend on it, and how big are the statues?
I would start with a darker base, like Warplock Bronze. The nice thing about warplock is that you don't have to paint brown under it (the coverage is awesome). Don't worry if it's not 100% covered over the black primer.
Then drybrush balthazar gold liberally, keeping your brushstrokes in the same direction. If you're spending more time on it, and/or it's a smaller statue layering works too, but keep the recesses dark
Then apply a wash: Agrax Earthshade if you want it dark; Reikland Fleshshade if you want it rich; and Seraphim Sepia if you want it in between.
Then drybrush Balthazar Gold again, or Hashnut Copper (whichever color you like more). Then, for the edges, drybrush Gehenna gold, and finally for the corners that that would catch the light, drybrush runelord brass.
This isn't esxactly the color you're looking for, but it gives you an idea of drybrushing statues in this manner would result in (note, I didn't use the colors I just listed, because I wasn't going for that coppery color) --
To achieve your upper photo, frankly, it doesn't look metallic at all to me. I would start with a slightly greenish dark grey, like Skavenblight Dinge, and wash it with a 50/50 mix of Nuhln Oil and Agrax Earthshade (or just Agrax, and then do Nuhln in the recesses, if you don't wan tot mix). Then drybrush that up with Skavenblight Dinge again, then Eshin, then Dawnstone. Then wash the whole thing with 50/50 Nuhln + Lahmian Medium; and finally, drybrush really lightly the edges with Administratum Grey.
When you're all done, and it's 100% dry, hit it with a gloss coat.