Orangetree
It's obvious you have not read all the documents relating to this proposal - it's certain you have not read the full details of the alleviation proposed/offered by the CAA (eg. the rolling totals averaging out at 40h per week!) - it's glaringly obvious you are unaware of the lengths to which EZ management will go, and have already tried to go, to secure what they have sought for 3 years.
The 'substantial' proportion you refer to is 6 weeks per year, with the other 2 being duties rostered and published the preceeding month.
The proposal also contains the caveat that, if, with gained experience, the reserve periods prove to be unnecessarily long, they will be reduced.
That beats the cr@p out of 52 weeks of random.