Northern has not, yet, declared its specific plans for 50% DOO or given a start date.
RMT is engaging in pre-emptive strike action when there are no specific proposals, as part of its wider campaign involving Southern and Merseyrail.
ASLEF is (or at least was) negotiating with Southern on a solution there, and I imagine they want to sort that dispute out before picking needless fights on principle with Northern.
I imagine a Southern solution would provide the road map for solutions elsewhere.
However, that seems a long way off at the moment.
Then perhaps Northern should show its hand, as by not showing it but alluding to things that may or may not happen just creates uneasiness, untrustworthy and a workforce whose morale will echo that that is on Southern.
The only solution wanted by hm government is widespread Driver Only Operation, so they have in theory tied the new franchise owners one hand behind there back, however the new owners knew as much as i did that the government wanted this method of operation.
The southern solution is 100% Driver Only Operation so is not the way forward to help resolve the Northern dispute.
Cant comment about the issue of Aslef, suffice to say its leadership is not flavour of the month by its own members, it seems they are as much out of step as the company are in knowing what there members want.