Trading one card for one of your opponents (a one-to-one trade) is usually considered the baseline value to strive for, but there are keywords that can help tip the scale more in your favor
Or, if they must
You may include 1 copy each of Professor Juniper, Professor Sycamore, Professors Research, Lysandre, and Bosss Orders in the same deck
Terrastodon is just a big elephant that can blow up a few non-creature targets but doesn't otherwise care about Omo's land strategy
Note how it triggers on enchantments entering the battlefield, not casting them, just like Archon of Suns Grace and Setessan Champion
When this creature enters the battlefield, create that many tokens that are copies of it.) Vigilance Whenever a creature token enters the battlefield under your control, put a +1/+1 counter on it