TL;DR unable to merge, or say hard to SORT the orders. Every IOU has different inside value based on different trading fee, withdrew fee etc.
Once they're approved by the committee they get standardized, all with the same stats?
Committee has no power nor technical support to do this. You can't force exchanges to store their coins in one wallet to be scanned, for security reason they may spread the coins in many wallets/addresses, technically after every transfer the address would change. You can't force exchanges not lend out coins for interests. Let IOU's be IOU's, let the issuers manage them.