It is not that they lack the knowledge or skill to build cities and develop technology
77/130 Jigglypuff
If you can pump up a creatures toughness high enough, it can survive the initial first strike damage and hit back
Firstly, you can get a trigger from Seifer the same turn you play it by attacking with a different creature, so thats already a good impact on the board
Just looking at the maindeck, you are countering at least 12 of their non-negotiable slots (Glistener Elf, Noble Hierarch, and Vines of Vastwood), along with some number of Growth, Might of Old Krosa, Groundswell, etc
You may have to wait longer than wed anticipated for these to get cheaper (they almost assuredly will and they will almost assuredly go back up, also) but thats OK because speculating on the price of Paradox Engine isnt really what we do here