If you're playing an aggressive or midrange tribal deck and you're only including sixteen creatures, you have to ask yourself: "Is it even worth playing all of these tribal cards in the first place?" If, for example, you only have enough creatures to have a couple in play at any given time, you're not maximizing your tribe's abilities
Sure, Ephemerate is aggressively costed, but it cant untap your lands, untap your mana rocks or perma-steal creatures youve temporarily gained control of
Fine, Magic
If you dont have Magma Spray (or Pillar of Flame, at the time), you had to get very creative with your blocking
This build already has a number of considerations to the planeswalker metagame
I used to teach Pokmon TCG at my local Mind Games and one of the first things I would discuss with parents and players is this topic