and also keep in mind not everyone has a high enough traz to simply fill their city with 2 slot buildings. First 10 levels are not enough to simply replace buildings, it'd only complement. I have 5 rogue hideouts with 3 slots each, I'm still running out of Rogues with a Lvl 7 Alcatraz. Given Alzatraz divides the output between all the types of units in your city it'd be impossible to get only rogues without dumping the rest of your army. Which would require either lvl'ing up everything else first so you can fight without losing more troops then the GE gives back, or having a healthy goods output or simply not completing GE.