The aim here is to kill people with damage, and the ability to have bigger creatures than everyone else, along with some really great Giants and tribe-specific cards, means you can do that knowing full well that people are going to struggle to retaliate
Valakut, the Molten Pinnacle's triggered ability has an "intervening 'if' clause." That means (1) the ability won't trigger at all unless, at the time a Mountain enters under your control, you control five or more Mountains other than that new one, and (2) the ability will do nothing if you control fewer than five Mountains other than that new one by the time it resolves
They also don't have a casting cost
However, those who were quick to criticize Gen 5s Fire-type Starter might now be having second thoughts after its first form Tepig was confirmed as a Pokmon Legends: Z-A Starterif this Ultra Rare (UR) card from fifth-generation TCG set Hail Blizzard [BW3] hadnt already changed their minds, that is
You could choose a different order for each one though