>For Edward I, filling his army with criminals made perfect sense.
But it works even in modern times.
Wagner group used to enlist criminals who were pardoned if they chose to join Wagner. Many didn't live enough to finish their conscription period.
Yes the same thing. Probably the thinking is along the lines "better for criminals to die instead of innocent people and if they die we don't have to pay for their accommodation and the society will have to worry about one predator less."
Probably they use criminals in the most risky of situations.
Maybe it's not very moral but the politicians are more worried about their calculations than about morals. Most of the times the difference between some politicians and criminals is just on which side of the bars they are.
You could argue that Wagner group itself is a criminal organization. They are even illegal in Russia, they have no actual legal backing. Not that it matters in practice, obviously. It is step further I would say - explicitly illegal organization, hiring from jail and even involved in actual organized criminality (smuggling, murders).
But it works even in modern times. Wagner group used to enlist criminals who were pardoned if they chose to join Wagner. Many didn't live enough to finish their conscription period.