Actualy there is no real good reason to sit on any leaders. It may make sense to wait a few turns for an MGL to be used, if no further elite battles are anticipated.
Maybe an SGL can be held a bit to get the next tech for a key wonder, but if you are crushing the AI so bad as to have a bunch of SGL's, what do you need to hold them for anyway?
No way the AI is getting any leaders and is probably to unproductive to build a wonder faster than you.
Come to think of it, if you have lots of leaders, abandon the game and find one that is a challenge.
Maybe an SGL can be held a bit to get the next tech for a key wonder, but if you are crushing the AI so bad as to have a bunch of SGL's, what do you need to hold them for anyway?
No way the AI is getting any leaders and is probably to unproductive to build a wonder faster than you.
Come to think of it, if you have lots of leaders, abandon the game and find one that is a challenge.