I had 4 letters of rec from Internal and 2 offline . Worked as a recruiter previous airline so got lots of time to talk shop with various recruiters . I asked about letters at United , I've heard of guys having 15 internal etc. Not living in a hub, nor flying for an express carrier I just flat out didn't know that many guys . Therefor only have 4 internals . Family etc .
He laughed and said sure they can help but the over all package/resume is looked at . Which I had plenty of others to fill any voids in areas I may be lacking. The recruiter told me some people look into these letters a bit too much.
Clearly can't hurt , I just giving hope to those like me who didn't have 300 United friends to write letters for .