The corkie and bait would go first due to the lead slowing down as it touches bottom.The simple thing to due is make all your leaders four feet then cut to size for differant rivers & situations.Then have some of those special longer leaders for that special time of use.Good luck,
STRIKE ZONE
I think what you are using for your presentation has a lot to do with how long your leader should be.For example,
1)When I use rag & sandshrimp my leader is always between 20 & 28 inches long.No matter if I'm drift fishing / side drifting or dogglin.
2)When I'm using corkie yarn or corkie egg my leader is between 2 1/2 & 3 feet long.No matter what I'm doing.
3)When straight dooglin say on the cowlitz / lewis
My leader is never shorter then 4 feet & never longer then 6 feet.