Eirikr,
No, I would not get rid of existing formations - Marshals and Vice-Marshals with leadership skill <25 would be able to use only offered formations (those existing), while those with high leadership would get access to new settings as I described.
I do not think that those leadership rankings are too high.
I agree with you that few people are training leadership and for those who do not train it in practice nothing would change - they would have the same options as they have now.
My idea is to encourage training of leadership (because I did not see much use of it) and first of all to give some benefits in the form of new options to those who spent their time and gold to train it proportional to their efforts (invested time and gold) in traing the skill, so those who spent couple of weeks and few gold coins training leadership to reach level 50 would get option to set their own basic formations while those who invested months and tones of gold on training leadership to reach 75 would have benefit to set formation for every single unit in their army.
As much as it would not be fun that everyone can become expert in leadership in few weeks, same way it is not fair that the one who spent half of year on training has the same options as one who trained for week or two.
I believe that for leadership rankings I set benefits from training are appropriate to efforts (time and gold) invested in training.
