You asked for an opinion so I will give mine but I would like to offer the caveat, that the only person's opinion who really matters is yours. If you like it, go with it. If you want to rescape it in a month, do so. If you want to keep it alone for 10 years, that's fine as well.
Anyway, I would dump one of the wood pieces as they look way to different to appear natural. I would make 2 hills in the back corners with your substrate, one smaller then the other, I would put down whatever wood you decide to keep first on one of the hills and then put all the rocks around it. Ideally, I would buy a lot more rock or wood that looks similar to whatever you decide to use so you can pick and choose what looks best and the amounts that look best.
I would play with various arrangements until happy and call it good.
That's what I would do if it were my tank, but it's not my tank, so kinda do whatever makes you the most happy
