I'm going to give you an example logain, since you brought up the PCL, and why I think the PPL will work.
Let's go off of the PCL drafting in a double draft style. Whoever had the first pick would have ended up with Jordan, Jerry Lucas, Kevin Durant, Dirk Nowitski, Swen Nater, Mark Jackson, Dale Davis, Mark Price, Tim Hardaway, Anthony Mason, Mookie Baylock, and Gerald Wallace.
I don't have to tell you that there's not a snowballs chance in hell all of those guys will fit under the cap. There would be years where Jordan and Durant alone would account for around 40% of the teams salary. In the PCL, Mookie Baylock (first pick in the 6th) was cut for salary reasons and was one of the first guys drafted in the offseason. Here, he projects as a late round/undrafted guy.
So, lets say that a new owner has to take over for someone that screwed up. There are going to be guys like Lucas and Nowitski (I don't want to name too many names, but I'm confident there will be plenty) available to draft. Not only will they be available, the new owner could decide to start with his very best year to make his team more competitive immediately. I would even consider allowing the supplemental player to have the same rule if other owners are in favor of it.
Like I told you before logain, I like your idea too. But I don't think the double draft and dividing draft pools should go together. There will always be All-Stars and even HOFers available to draft to turn a team around with how I've set this up.