Building stock

So, after cutting bulkheads, I need to build a stock for the boat.
There are some suggestions by the designers about how to make building stock in different conditions.
The first thing you should consider the ground. I have pure soil, clayey and hard ground. I don’t want to
make concrete base, but I must ensure that the ground will be enough strength for support the boat during building without any shift.
My solution making special plates under the plumb posts:

Building stock is made by pine wood. Poles and horizontal plank as well. The base of the poles are spiked to the soil ground with special paw plates.

The stock plan came with the drawings from the Designer. I’ve made the CAD drawing by the plan.