they seem good to me!

A Fort yes. A Fortress although should be a stronghold to withstand.  In 0ad an ungarnisond Fortress is captured that fast that an upcoming  100 solders+ Army is not noticeably slowed down at all.  Sometimes foreward structures to bother an attacker only helps him more  to concentrate his army, than to help you to organize a defense. I would like some techs to make buildings stronger. e.g. Fortresses could be ramped up with an outer bailey. Giving them more of all, especially a larger garnison like Han-Civic Center. I would also like when "sentries tec" would be like a garnisoned unit in all aspects, so that fully equipped tower is like 6 garnisoned units and fortress 21. (Could be a citizen soldier normal and a champion with professional garnison tec combined)  

I really play hard to prepare me to defend my self against the IA in very hard, but if i play with just 300 pop population and in medium size i will fell very lack of emotion to my mind and will fell very unsatisfied

Ok, thanks! I'll give it a try

Elephant Stable: Before After: