Think that believing that the Unite leadership want this strike is a slight simplification of things. The people formulating the reason for striking are the branch executives and the people who have the power to determine whether those reasons are a load of tosh or not are the members. It's up to cabin crew who are still members of Unite to say whether they want to strike. Of course it behoves the branch executive to ensure that they have spelled out what the potential effect of striking will be - loss of pay, possible loss of perks, likelihood of being sacked - otherwise they are leading the membership up the garden path. Don't know if the union can be sued for issuing incorrect legal advice.
I don't see cabin crew making particularly good sacrificial lambs. As a workforce they are reasonably middle class and the cause is not going to set the comrades in the wider union's hearts aflame with indignation. However, it does allow the union to test the water around the legal angles on strike action without seriously discomforting the bulk of the members. So whilst I don't believe that the leadership will instigate a strike, I don't think they will stand in the way of the branches want to have a go. After all, what have they got to lose. BASSA membership is dropping and it is patently clear that MF cabin crew will not join it in its present guise. I can see that when this dispute eventually ends Unite may wish to set up a new branch (or radically overhaul the BASSA/CC89 set up, possibly merging the two to form a single branch with a new name) which will have none of the baggage of the past, to represent cabin crew.