The business of Generals taking jobs with military contractors is a difficult one. Where the heck else are they supposed to work?
I don't know how things work on your side of the pond but over here, Generals (also Judges and some other positions in government) don't retire at all they are put on rest meaning no active command, they however keep a large portion of their pay until they die and keep the title (and many of its benefits).
I fail to see why they should be accommodated in a different manner compared with other government employees.
Most Generals stop working at or close to retirement age anyway, why should they be entitled to earn so much extra over an already very good 'pension -pay'.
Don't get me wrong, I don't mind people working past their retirement entitled age but why agree with the mechanism that exists now which is way too easy to be corrupted (again, not saying that those who do are automatically corrupt).
The idea that Generals or other highly trained and educated military employees post retirement can only work for the defence industry, and more specifically the part of the industry they used to work together with while enlisted, is a too easy excuse.