Maybe I don't know. I don't think anyone else does either. But the fact is, if other teams offered more, we either would have heard about it or the Saints would have taken the better offer. The safe assumption is that Loomis took the best legitimate offer. Other offers might not have been serious. I'm not exactly sure what else Loomis is supposed to do if no one else actually made a better offer.
Things change. Teams valuing coaches vs draft picks vs players change all the time. IIRC, few if any were expecting to get what was offered for Gruden. Teams just value their 1st round picks too much to part with them unless it's part of a huge package of picks or players. A coach isn't normally gonna pull a 1st, let alone 2.
I just think even if Loomie holds out for a bit more, I'm not so sure it makes any difference.