I agree, this is such a great deal. I get units early as garrison defense and of course get to play with them even before I’ve come close to researching the tech to build them.
That and garrisons make siege defense just way more interesting to me. And it was brilliant giving the defender advantages to defense but not just that cumbersome wall in AOW3 that just turned into a bring catapults and launch boulders at the gates every time affair.