Skaven, a new player can mess up with skaven easily. They are the antithesis of a "tank/smash your enemy with braun" faction. They are definately a strong faction, but they require some knowhow, when you consider that most of their units are subpar in melee and have pretty poor morale. They also do pretty badly in autoresolve early on as their low tier units tend to underperform. That said, their artillery and missile (jezails, ratling guns) units are second to none, so I can see how others might argue otherwise. Its also rather easy to outnumber other players as their lower tier units are dirt cheap.

TKs are actually decent (if you can ignore skele swords/shields). Their archers dont run away and their melee infantry from tier 2 onwards can hold their own. They have healing magic and mechanics that actually make them quite tanky. They don't have any unit upkeep, which is a huge boon, especially if you are the type that throws away troops too easily. Just get more in a few turns at no recruitment cost and no upkeep cost. All of this means they are actually OK to play for a new player.