I think what Mac & Will need to do is get rid of all the voices from outside - managers, producers - and craft some demos.
Spend some time alone together, putting as much focus and energy into the creative process as they put into making the Crocs/HUH shows a success. Once they've got demos for twice as many songs as they need for an album, then bring 'em to a talented producer or objective ear and start weeding, and put an album together.
The thing about Evergreen - they had a LOT of material - just take a look at all the B-sides that came out. Same with WAYGTDWYL to a lesser degree. Since then, the b-sides have all been reworkings of existing songs - radio recordings, instrumental, live...
Seems to me that whhen the've gone into studio from Flowers on, they've written and formed the songs in studio... under the pressure of paying for studio time. No quality can come out of that. If you don't have the songs to take into the studio and record, than don't try to mane an album until you do.