Close board fencing on slope

Hi.
Building a short close board fence (16ft) and want to make the top level to look nice with the house behind.
Issue is the ground slopes uphill, maybe 150mm (6’’) higher one end with pavement prevent outside.
Thinking about levelling posts and arris rails but letting the gravel boards (concrete) follow the ground next to the pavement.
consequently the close board part of the fence will taper slightly from one end to the other.
Is this weird?!

you can if you want to

or, you can scoop out a small trench for the concrete gravel boards to sit in. This will prevent weeds or animals getting under the fence, so include Hedgehog Highways in at least all corners of the garden. If you set the gravel boards in concrete you can lay it while you set the posts, and this will hold together and support the posts against leaning under wind pressure

Or, you can use 12" gravel boards at the low end, and 6" gravel boards at the high end, then you will not need to do so much trenching.

All that matters is that it looks ok, I built a 3 sided fence to hide an oil tank, probably about 10m long and on a funny slope but the tank is level. So I decided to keep the top level, most of the boards were cut to different lengths, sort of stepping along the slope

Thanks.
Thinking I might make the gravel boards level with the fence. At the low end there would be maybe 1'' gap which I would partially fill with tarmac repair and the high end maybe 4'' of the gravel board would be below ground level.
Neither ideal, but I want to avoid the fence sloping upwards and not being level with the house.
Brick walls seems to be laid level and sort of go into the ground, so a similar approach I guess.

This is what I did but don’t like it.
Will redo with double gravel boards one end and a single the other so the boards are uniform height.
Dammit!!!!!!!