I don't know I like it as it is... Something strangely Zen about it.
Is your substrate final? I almost feel a Southwestern red desert-ish thing. Maybe a red/brown substrate, some red/brown rocks with hard rough edges. The hard broken edges would counter the organic curves and shape of the driftwood.
First, the fact that you are thinking about the layout before setting it up is commendable. Well done.
Second, the stark contrast between the white wood and the black substrate is something you need to take into account. Is this the look you are after? In fact, what is the look you are after? You need to start with the end in mind.
Lastly, don't place the main focal point in the middle of the aquarium. Use the rule of thirds to positioning it in a more dynamic place. Here, I would combine the two pieces to look like one mass and move it to the left so as to sit at the one-third mark.
I have a lot of examples of this on in the aquascaping analyses I do on my blog in case you care to see examples by top aquascapers.
I'd try scooting them both to the left some, and closer together (basically what MiamiArt said). This would create more of an off-center focal point. Or you could place them on each side of the tank facing one another. Maybe with the big one on the left, higher side, and the smaller one lower to the right.