That is true, shun - only Felder was an add-on.
MC, from all the accounts I've ever read, Timothy did not want to sing Randy's songs when he joined the band. I think he probably wanted to pave his own way in the band rather than to just be looked at as Randy's replacement. I agree with you that Timothy is a tough cookie. He has a mild-mannered demeanor, doesn't want to always be the center of attention, but yet doesn't seem to be easily intimidated. It is this combination of traits that makes him a perfect fit for the band, IMO. I don't know how long it took him to get acclimated in the Eagles, but I suspect it wasn't very long. If I'm remembering correctly, the band was out touring again within a few months of him joining.