I don't think you understand the implications of the court action. The action was over whether ASLEF had the right to tell its members not to work 12 car trains. The court said it did not. The court also said this applied to new traction generally. So if a company tells a group of Northern drivers that they will be learning to drive DOO train then the drivers will have to do it.
On Southern the drivers did go on strike but when they were working they were trained to operate DOO over new routes and DOO was introduced over those routes. Even before the final agreement had been made all the routes had already gone over to DOO.
Sure you can go on strike and make it difficult for the company. The only way you can stop it would be to go on all out indefinite strike.
The difference is Southern has DOO in their contracts for passenger trains so it was easy for GTR to go to court and claim they could do it as the 12 car agreement was on dodgy ground and more of a 'gentleman's agreement' with management that have long gone. The court agreed with GTR. Northern drivers on the other hand do not have DOO for passenger trains, so it would be harder for the courts to 'force' DOO. An agreement would have to come through the usual collective bargaining channels. ACAS would probably get involved.
Arriva are hitting a stalemate. The RMT won't agree trains without guards, their compromise is drivers opening and guards closing as per Scotrail. Even if Arriva agree, the DfT and Mr Wilkinson won't be happy with the outcome as this is not DOO. So presumably when these new units arrive, Arriva are going to have to directly approach ASLEF.
I can see them having to go back to the DfT and have frank discussions about their next moves. Arriva have bailed on the Welsh franchise, Chiltern isn't making enough money and XC needs some serious fixing in the next franchise.