Resin Forest Bases

Long time no post, but without dwelling a quick look at one element of what I'm working on now.

I ordered a load of resin forest bases from www.back2base-ix.com. These are for use with characters, elites etc. and the first guys destined for them are the Ratlings that I'm just starting painting.

Do you think this looks right? I wasn't sure about the grey, its a nice contrast I think, but will it look out of place? I suppose I could try a reddy brown instead to blend a bit more?

Anyway I really don't want to end up doing shed loads of test tree trunks! But tree trunks are pretty prominent on all the larger and more interesting bases I'm putting together and they have to look right.

At the moment its Rhinox, black wash then drybrush Adeptus Battlegrey and Zandri dust.

Would appreciate others thoughts/suggested colours to use.