its the only thing so far i have seen that uses political favor, but im sure there will be more to come as i progress. should i save them or build out posts? does any one have an idea on how effective 90 defense is during an invasion. space for space it seems like theres nothing close at 90 for 3 spaces. i just dont know how big of an effect it has on invasion success or failure...thanks

90 defense = 90 invasion def (reduction in invasion success %)
But 90 defense also reduces damage when under attack.
Your call. 90 defense do use more space than invasion defence