Sounds like mid tier might've been a good option for you.Moving half of it to a different field. Been down there with my fork. It's just too sad and wet to cultivate.
Got the salt and potash on the other field today. It's a light field and will plough this week.
The clay area of the originally intended field has two poles in it, a curved edge and the ditch could do with cleaning out though it isn't bad so that's what we will do there then get it in with under sown spring barley later. It will make a good grass paddock and the sheep will be able to access the beet tops from it.
I think generally we need to be cutting out "non starter" crop/soil type combinations and odd shaped patches with obstacles from the arable rotation. We can no longer afford to try it and see what happens or spend a fortune establishing a crop in bad conditions without there being a very good chance of success.
There are quite a few other triangular gearings of clay near watercourses that would also make useful paddocks for the sheep and cattle, and would leave the rest of the field an exact width of tramlines nice and square, with easy working soil.