ᐅ Terracing on a steep west-facing slope using wood

Hello everyone, I want to add some (not continuous) terracing on a steep slope to better plant willows and other vegetation. The slope is stable, with light ground cover, very dry, rocky, and steep. The neighbor has already nailed boards at the top boundary, and my property starts from there. This is how it looks:

I want to achieve something like this:

or something like this with boards

My idea is to use screw anchors instead of metal rods or wooden stakes.
What do you think? Should gravel and drainage membrane be placed under the boards or black locust posts?

I’m not entirely sure why you want screw anchors. They are usually used as a substitute for pier footings, not for posts.
Option 1 looks better visually; the one with the boards seems very makeshift. If you use locust wood (Robinia) for the posts, it will last a very long time.

Thank you. Screw anchors only for one reason – the slope is rocky, so driving in the posts will be difficult. I thought screwing them in would be easier and that the screw anchors would hold better. Do I need to consider using dimpled membrane and a gravel base (I got this from an instruction guide)? Or just drive the posts in (I was thinking about driving them in 100cm (40 inches) and 50cm (20 inches)) and then lay out the cross rails?

Where you can’t drive in nails because of the stones, screw anchors won’t work either.

Metal posts could also be an option, but I quickly couldn’t find any. How deep do the wooden posts need to be driven in – at least 50 cm (20 inches)? It’s not easy to reach the spots with any equipment, so everything has to be done manually.

I also doubt that screwing into rocky soil is much easier. I would definitely not set wood in concrete as described in the instructions. Eventually, every wooden post will rot, and then you’ll have to start breaking up the concrete. It’s better to invest in quality wood.

You need to drive in at least one-third of the post length. There are also drive caps for power drills.