the mempool
There is no such thing as
the mempool. Thus, you have tried to build a lofty tower on a wholly nonexistent foundation.
Each node has
a mempool, consisting of unconfirmed transactions it so happens to have heard of through Bitcoins gossip protocol. Each nodes mempool is different from the others.
Correcting this single error in thinking about Bitcoin can correct many other errors, too.
Spinning around what achow101 correctly explained: We already have a coordinated ordered transaction mempool, as you call it. Our coordinated ordered transaction mempool is called
the blockchain. Transactions are coordinated and ordered by
the blockchain, through the very same confirmation process as you attempt to shortcut. What you are really trying to do is to invent a replacement for the whole proof-of-work mining system; and obviously, you have not done that.
P.S., it is also impossible to descramble eggs.