The only conclusion I have drawn from the Ofsted report is that Roke is inadequate and its current management and governors are judged incapable of delivering the required improvement. That is Ofsted's conclusion and they are the final arbiter in the current system. You may disagree with their judgement but legally their judgement is final (barring appeals).
Having external intervention from the LA does not prevent the DfE from intervening.
Professor Machin said that the results cannot be extrapolated to the successful schools now being converted to academy status (converter academies) as these are different to the academies set up under the last government, which were converted from or replaced failing schools. The study found that conversion to academy status did bring about improvements in failing schools that became sponsored academies under the last government with the biggest improvement being in community schools that converted. If you want to say this study does not apply to Roke the angle to take is that it does not apply to primary schools, which I think is a bit weak, or that the study got it wrong, which I think is a stronger argument.
I am aware of the work of the Academies Commission. I'm not sure how that is relevant to Roke.
There must be a consultation for Roke at some point prior to conversion but I agree it will probably be a sham. I am not happy about that. The reason the consultation requirements are so weak is that, under the previous government, campaigners were able to use consultations to prevent some failing schools from converting and that the evidence available shows that such schools did not improve as successfully as those that did convert. For clarity, I am not saying that I personally agree that this should have led to consultation becoming a sham. I am not sure what I would have done if I were in charge of education but it certainly wouldn't have been the current "consultation" system.
Given Ofsted's judgement on the governors and management of the school it was always likely that they would be taken out of the equation by interventions with the DfE stepping in if the LA left the governors and management in place. I wouldn't necessarily regard that as bullying. If the school's management and governors have got the school into the situation and are judged incapable of delivering the required improvement we either wait around to see if they can improve, and risk delivering a poor education to more children in the process, or we accept Ofsted's judgement and get on with replacing them with people who can deliver improvement.
I have tried to avoid expressing an opinion (although you clearly think otherwise) but I will express one now. Whilst I can see the DfE's case, I sympathise with the school's desire to have Riddlesdown (which you've called Ribblesdown a few times!) as their sponsor. If it was working and producing the required improvement it is a shame that they are being pushed out in favour of Harris, however understandable that is from the DfE's viewpoint.