Garrosh's education and upbringing, Garadar started as a Pox camp. Later, it became an asylum for Maghar and other orcs fleeing the old Horde. However, it wasn't always as simple. He was sick when he was younger but he didn't always get sick. It's logical that Garrosh as well as other young orcs , received training and guidance from older orcs or recovering to RS gold safeguard villages from invading clans, angry elementals, or the ogres. Garrosh, I believe, was the best Garadar orc at the time of his combat. The lack of enthusiasm or apathy, however it's relatively unfamiliar to me. Garrosh is also described in the novels as a person who battles Kor'kron daily. When he fought Cairne Garrosh's tactics are described as strong and powerful, skilled, but his youth and confidence were eclipsed by the wisdom of the elder tauren. Saurfang also claimed that he was an outstanding combatant, and had no rivals in combat but his leadership was inadequate and he was often unable to see the bigger picture since the focus was on the up-close and directly in the face. This is in contrast to his natural genetic predisposition to become an extremely skilled warrior (he came from the Warsong clan). Garrosh is a great warrior with very few shortcomings.
It's my opinion that because Thrall did not keep his abilities and abandoned them to the side in favor of his shamanistic skills and because of cheap OSRS gold Garrosh's expertise and genetic makeup... it's not a surprise that Garrosh was winning until Thrall invoked the elements.