I would think that the ultimate aim of the families is to prevent similar pain and anguish from happening to others.
While some relatives have been left high and dry by the loss of the income from the deceased Servicemen, it seems that legal action is the only thing to which the MoD and the Gov't will react. If only Gov't would just accept their failings and CORRECT THEM - not with platitudes but with a ferocious desire to protect their assets that include ships, aircraft, vehicles Servicemen and women.
However, far too many senior people have trusted to luck in pursuit of New Labour's foreign policy since 2001. If it takes legal moves to get them to realise that it costs a huge amount of money to go to war, then so be it. Next time, perhaps our politicians should think twice before agreeing to be the US lap-dog. Either that or thoroughly equip and protect our troops.
Perhaps the MoD should sue the Gov't Treasury for lack of sufficient funds to wage war?