I'm one of the ones who believes that Somebody could've been a Glenn solo song. As I said in my review, it reminds me of THIO or Smuggler's Blues. That being said, there's something that Don Henley said in the documentary(I think it was the doc), that I think fits. During HFO, while discussing the solo songs, he said something to the effect of "most of these songs could've been Eaglrs songs". I think that Somebody would've been a great Glenn solo song, but it's also a great Eagles song, and one of the best on LROOE.
I haven't thought of LROOE being a collection of solo songs, but now that I think on it, it does seem like it. (Exceptions being NMWITW, How Long, WITW, and LROOE). While they could be solo songs, there's something about the group aspect that makes it better. Although, they didn't record together as a group, did they?
As for Glenn, I do believe that he really downplays his talent as a whole, and it's really sad that he does this. From the doc, and the live footage I've seen since the reunion, to me he still thinks along the lines of "we've got Don Henley. Why do I need to sing?... Joe Walsh is our main guitarist" why do I need to play lead?" While that maybe true, his voice is different from Don's, and some people like his voice more than Don's(myself included). As for guitar, having watched the Live in Dublin dvd, I've come to believe that he could (no can) play some great leads if he wanted to.
It's ok to complement others' talents by cutting back on yours sometimes, but not all of the time. Imo, Glenn sells himself short too much, and it's a shame.