Leave it to this board to take a compliment to the band and twist it into a negative. I know how good the guys are. I've spent literal decades playing their stuff. Hell, I have found one of the chord changes in Sour Girl to be harder than learning a solo from someone considered a "virtuoso."
All I was saying was, as a band, the whole was greater than the sum of its parts. And I think if you look at Scott solo, Army of Anyone, Talk Show, and the current version of the band, as good as they were, they don't touch STP at their best with Scott.
As far as writing songs for others, Dean cowrote a song on Chris Robinson's first solo album, and he also cowrote a couple songs (and played guitar) on an Alanis Morrissette record 15 years ago or so. Robert cowrote an Earth to Andy song called "Never Be Cold" (by ear, it sounds like he wrote the bridge) and Robert was asked to write a song for Ozzy several years ago but it didn't end up on the album. That's what I can remember off of the top of my head.