RE: 308 for moose
I see your point on the middle ground but the point is still the same. There are many women and young kids out there that like to hunt elk and moose but can' t handle recoil very well. I am 6' 2" and weigh 245 pounds and can handle just about any gun out there. My son, when he turns twelve, will be going on his first elk hunt with me and he will be about 5' 5" and weigh about 115 pounds. What rifle (cartrige) should he use?
No it is not written that someone will be a great shot if they use a sub 30-06 cartrige but they have a better chance of being a better shot if they don' t get kicked around a lot when they practice. And no you won' t gut shoot animals just because you shoot a medium bore magnum, but my almost 12 year old son wouldn' t like shooting a 338 mag. and almost certainly would not shoot it well. He will probably start out with something along the lines of a 7mm-08 or my 270 and work his way up from there just like your kids did.
I' m just saying there is good and bad to everything and as far as guns and recoil go each person has their own limits and i would rather a person be comfortable in shooting a rifle than be worried about having scope eye. Yes, like you said they need to be tought how to handle it but you can' t start them out at the top.