The competition should be very good. If, and it's a HUGE if, everything pans out the D Line could be dominant.
I don't know about dominant, but bringing in Will Smith for depth, Easley as a potential stud, re-signing Wilfork, and getting Kelly back means that it will be substantially better than last year where Ninkovich and Chandler Jones did a ton of heavy lifting but were gassed by the end of the year.
DE: Chandler Jones, Ninkovich, Will Smith, Buchanan, Bequette
DT: Wilfork, Kelly, Easley, Chris Jones, Siliga, Armstead, Vellano
This is supposing they don't add another DL soon. Easley and Armstead also have hybrid positional versatility.
Last year they carried 8 defensive linemen at all times. Jones, Ninkovich, Wilfork, and Easley are locks. I suspect Kelly and Siliga probably make it as well. That leaves Smith, Buchanan, Bequette, Armstead, and Vellano to battle it out for 2 spots. My guess is Vellano and Bequette are gone, meaning the camp battle is to see which of the three of Armstead, Will Smith, and Buchanan gets sent packing.
It's interesting because you have two intriguing young guys who haven't done much of anything and a salty vet who as recently as two years ago was one of the better players at his position in the league but has barely played since. My guess is you'd rather have young guys given Smith's injury history doesn't mesh well with the recent injury history of guys like Easley, Wilfork, and Kelly.