That's very true with regards to the culture. I hadn't though of that!Very interesting list! Let me add my two cents:
- Heroic Epic is quite useful: a) When going for a 20K victory - 4 culture for only 200s quite early is very strong! b) When doing "leader fishing", it will increase your odds for an MGL from 1 out of 16 to 1 out of 12. That's nothing to be sneezed at!
However, as far as probability goes, I can give you the example of my 2 most recent games (Note: I'm not just pulling out extreme cases from all my games, these are my actual 2 latest games).
In the previous game, I got a great leader with my first battle with an Elite. I rushed the Forbidden Palace. I had 4 other Elites units, and in the 2nd battle I already got another leader. That is 2/3 battles- a 66.6-% leader rate, in a non-militaristic civ without a Heroic Epic.
In my current game, I have 9 elite units. I can't tell you exactly how many elites I've lost, nor how many elite battles I have won. Thinking about it as hard as I can, I am going to estimate that I've won about 25-30 battles with Elite units. I haven't gotten a single leader! If i were to get one in the next fight, that would be roughly a 3% leader rate.
The game's default leader rate, as you mentioned is 1/16, which is roughgly a 6% chance. Compare that to my most recent 2 games: 66% and 3%. I wouldn't put too much weight an an improvement from 6% to 8% haha. EVEN if the game's probability were a little more consistent, that is still only a 2% increase. That is really not worth 200 shields. That isn't even worth 50 shields.
200 shields are roughly 7 Swords (likely overrun). Swords become MI. 200 shields are roughly 7 Horsemen. Horsemen become Knights.
In the end product you're playing with 7 less knights/Medieval infantry for a 2% chance. If you consider that even in the first encounter, 2 of those units are likely to become an elite, and you have let's say 7 elites already, then you've already increased your chance of a leader form an Elite victory by 28% from now having 9 elites compared to 7 before.
210 shields for a 28% higher chance of leader, or 200 shields for a 2% chance.
And that is not even counting the obvious impact that 7 additional units will have on your game.