The 1GG cost is also pretty restrictive. If you're running Birds of Paradises for your mana base, chances are you won't need/want a 3cc 1/1 because you're obviously ramping up to something bigger. If you're playing G/W humans, then you'll probably be playing Avacyn's Pilgrim. Which means your second land must be a Forest/Dual as well in order to cast Champion of Lambholt on turn 2.