I'm having a really hard time comparing our "T49" and "T50" plans! 
Here is a short list of pros and cons from the perspective of the latest plan you posted (I'm comparing EOT50 states of the two plans):
Pros:
Cons:
I think the key difference in getting the settler out earlier is that you did not whip the workboat in the capital and thus got more mine turns in at the cost of some food. I need to try this approach myself and quantify the differences more accurately before I can make up my mind
Here is a short list of pros and cons from the perspective of the latest plan you posted (I'm comparing EOT50 states of the two plans):
Pros:
- City C is one turn earlier up with appropriate support!!
Immediate benefit is 5 food and 2 commerce, but the real beef is of course the fact that the city will be 1-turn ahead of the pace for the entire game assuming we can provide the necessary worker/happiness-support.
- City B has +1 pop
- Agincourt with roughly +40 hammers
Cons:
- Agincourt has -1 pop
- City B has roughly -40 hammers
- 3rd worker is 1 turn later out
- Note that the extra pop point in Agincourt is more valuable than the pop point in City B, because City B does not have a 3rd improved tile to work yet (and because of larger food box).
I think the key difference in getting the settler out earlier is that you did not whip the workboat in the capital and thus got more mine turns in at the cost of some food. I need to try this approach myself and quantify the differences more accurately before I can make up my mind