Just like their edge defenders, New England also features two types of defensive tackles on the roster- the big space eaters, and the quick penetrating attackers. After investing their past two first round picks on defensive tackles (and their past four first round picks on the defensive front seven), the Patriots have shown a clear intention on improving their interior pressure.
You might have noticed the absence of Zach Moore in the edge defender evaluation. There have been observations, most recently noted by NESN's Doug Kyed, that Moore has bulked up his frame a considerable amount. I believe that he will kick inside to provide depth with Dominique Easley and Chris Jones as one of the penetrating defensive tackles. Whether or not he makes the team remains to be seen.
The Patriots are flush with big bodied trench fighters, a testament to the increased usage of the 3-4 defense in 2014. Sealver Siliga, Alan Branch, and first round pick Malcom Brown should be considered locks to make the roster, and also offer the top three linemen in the 3-4 front (with Siliga at the nose). Behind them is Joe Vellano, a starter in 2013 out of necessity, turned practice squad player in 2014, he has a big fight to make the active roster this year.
New England also signed Antonio Johnson, a 6'3, 330 lbs monster, in the offseason, and just recently added undrafted rookie Vince Taylor, who has plenty of experience as a 3-4 nose tackle.
These defensive tackles provide some interesting combinations based upon down and set, and is really going to be reliant on Easley taking his game to the next level as a sophomore. On run downs, Brown and Siliga can clog the middle, while on passing downs Easley and play with whichever edge defender kicks to the inside. All of these defensive tackles can play in both the 3-4 and 4-3 fronts.
Siliga, Easley, Brown, and Jones are all under 25 years of age, which means the Patriots have one of the brightest young defensive lines in the league. This off-season will go a long way in solidifying their ability on the field.