Niether as the monarchy cant decide whether or not we go to war anyway, and as we saw in iraq, its fine for peasants kids to die in conflict but not the posh kids
I think we are more likely looking at someone spoilt and being used to having what they want, so rather than having to pick one or the other like everyone else HAS to he wanted both so he is getting both
The only other thing that springs to mind is this
If he can be reasonably placed in the RAF or navy he can then more easily have a posting that keeps him out of danger in any conflict, whereas with only one forces training he would, as he is be permanently in one regiment, so if that regiment goes to war he also should