Patriots TEs caught 169 passes for 2387 yards and 24 TDs in 2011. Gronk and Bennett might not match those raw numbers in 2016, but I think those two could provide a better offensive combination than the duo from 2011.
Bill Belichick has always liked having 2 good TEs on the roster because that personnel grouping gives the Patriots more versatility in their offensive looks, especially out of base/12 (1 RB, 2 TE) personnel. When the Patriots won 3 titles in 4 seasons from 2001-2004, the main TEs were Christian Fauria and Daniel Graham.