They seem to identify as hardworking farmer types, who are knowledgeable and capable of getting stuck in to working the land and turning it around with their labour and their expertise. This is what Bill Cole was buying into when he gave them the tenancy on such favourable terms.
But where is the evidence for this? We know that Tim was a gardener for the National Trust (which would be largely maintenance in a very neat, well-tended plot with a team of volunteers) and Sally was born on a farm. Other than that, he's a plasterer, she's a bookkeeper, they lived in a town, they go off on very long walks for months at a time, she writes books, deploying lots of nature references, but none of that actually points to any significant farming going on. She talks the talk about rewilding - nourishing and tending the abused, neglected land etc, but it seems like it's just words. Especially as they've actually owned land she dismisses as a 'bramble patch' in France for almost 20 years and are letting it slide further and further into genuine neglect.
It seems to me they scored themselves a cushy billet on this fabricated farmer identity and had to tell more tall stories and do another runner when it became apparent they were doing sod all on the land.