Tough to gauge what actually gets you called. I know a guy who just got hired with a little less than 2800 TT and 600 TPIC. No internal recs or letters. Maybe it depends on having a good range of experience in your background and evidence that you can make it through their training program. Maybe it matters which regional/legacy feed they are extracting you from. Maybe it was the lavender butterfly at the top of his resume that did it.