If I was just starting out I wouldn't go with 223 when a 308 will out shoot it any way you want to talk about it. Why limit yourself to really under 100 yards most of the time when the 308 will kill out to who knows where. Now for all the 223 lovers that claim 200 yard shots remember he is new and may not be able to hit a hog right behind the ear at that distance.
308 hands down.
New to hunting, not new to shooting but I do see your point as shooting from a tree stand would be much different than from a solid rest at a shooting range. I doubt I would be bold enough to go beyond 100yds without knowing for sure it would be a DRT type shot. I don't want to be "that guy" that is out on his first couple of hunts and loses everything he shoots at.