Orcs – discussion about the race.

That's correct. And Orcs are indeed underpowered in duel mode. I tried playing as them, but oh my! They got crushed like kittens. On the global map, Orcs are quite effective in battles against any race, but relying on them is only worthwhile with prolonged, non-confrontational development against the opponent. Orcs are only strong at high levels of development.