If this is being looked at purely from a finance point of view then apparently the only way to save money is to remove an entire platform (harrier, tornado argument).
We have around 60 chinook, merlin, apache and wildcat and 24 puma. Can 2 wildcat deliver the same number of pax into a urban environment as a single puma possibly? Can puma do the wildcat job on ships no. Chinook does heavy lift and merlin stays as its the only asw a/c we have left and both are currently in afghan.
IF we have to lose one for financial reasons next year then puma looks vulnerable unfortunately any subtle capability argument doesn't seem to matter all that much to those in whitehall.