3e feat leadership was of marginal use. People mostly used it to get free heal bot follower one level lower than party, cause you get permanent cumulative penalty to your leadership score for every cohort that gets killed. Followers were even worse, you got 5-6 lv npc-s who would get killed easy, which in turn, again, lowers your leadership score. In my experience, Leadership was one of those feats that sounded great on paper, but wasn't worth it in game. Strongholds were not in the core books, but in one of many splatbooks.
In 2ed, you get stronghold at level 9.