I think Glen could've fit in with the Beach Boys - if he wanted to. Could you imagine if Al would've moved to bass, and Glen Campbell and Carl would've shared guitar parts? And think what he could've added vocally. When you look at some of countryish songs that the Beach Boys played in the early/mid 70's, Glen would've fit in nicely. Of course, then we never would've had those great Jimmy Webb/Glen Campbell songs...
I'd like to know what Al and Glenn could have written together, since both were/are into Country/Folk.