Shining Armor's shield spell is strong enough to cover an entire city and keep an army at bay for several hours. If he were to use that same amount of power for a personal force field, he could easily defeat Steel long before the shield broke. Furthermore, even average ponies are capable of feats of strength well beyond any human, and Shining Armor has been shown to be an exceptionally strong pony. Therefore, superhuman strength is not the advantage that it normally would be. It simply levels the playing field. Finally, ponies have been shown time and again to be extraordinarily tough, shrugging off blows that would kill a human instantly. On the off-chance that Steel could get in a shot before Shining got his shield up, it most likely would not be a fatal blow. This one goes to Shining Armor.
Waitwaitwait... Shining Armor versus THIS guy? Spoiler: Minor language [video=youtube;Q2-pHvqq_BQ]http://www.youtube.com/watch?v=Q2-pHvqq_BQ[/video] Shining wins. Flawless victory. No argument necessary.