I mean, the problem here is they aren't singling out people based on performance, it's just across the board redundancies. And as one of the unions pointed out, the number of government workers should really be expected to grow as a proportion of population (since they'd have more data to manage), but the actual numbers haven't shown that. To some extent this could be explained by more efficient processes with computers replacing actual sheets of paper, but 55 years without growth is a long time
Also, if you're just wanting to cut dead weight, why would the dead weight take the redundancy package when they could stay in their cushy govt job until they retire? The ones who'll leave are the ones willing to work at a new position and think the benefits of a govt post don't outweigh the downsides anymore