Longevity certainly matters (so Ifill over Ball, Davila, Burns) but performances are more important (so, for example, Roly over Bertos, or Cacace over Doyle).
None of the guys you mentioned are close to Ifill right now - if Taylor stays another two-ish seasons, which he will, and we achieve some decent success I'd see him in the top 5 ahead of guys like Daniel, Brown, Greenacre, Siggy
Top three for me right now (in no particular order) is Krishna, Durante, Ifill, and I suspect that's the same for most guys here. Past that it's murky