That question isn't as clear as you may intend it to be.
If we are playing in the Theme Format of the PTCGO, there is no "rotation". All older Theme Decks are legal, it is just that Theme Deck quality has been steadily climbing over the years, and it seems like the beginning of each series (BW, XY, etc.) sees a significant spike.
If we are discussing which Theme Deck is best for someone to buy with respect to the 2018 Standard Format... Mach Strike helps you on your way to a budget deck but not by a whole lot. Tropical Shakedown might be better for it, because Alolan Exeggutor isn't bad for a budget deck and there are rumblings about a competitive deck for it in Japan. Hydro Fury has Magcargo.