But you only have a third chance of being one down with a 33% worker. See mrpony's post for a reasonable guess at the impact.
Final word from me, the above is not a valid analysis.
A 33% worker is a 100% crew member of any given flight complement.
77
Your are right, my 'one down' was in reference to the legal minimum crew, not the industrial agreement. Apologies for any ambiguity.