We have some exciting additions (Bennett and Avril) and some open questions (will Branch return? if not who replaces him?) on the DL. I thought I'd look at snap counts (found via Football Outsiders) last year to help project what the rotation might look like next season (and what the remaining holes are).
For our starters, we played Clemons on 87% of snaps, Bryant and Mebane on 62% each, and Branch on 56%. The "rotation" guys were Irvin on 43% of snaps, Jones on 32%, McDonald on 29%, and Scruggs on 20% (no one else played more than a handful of snaps).
How about the new guys? Avril played on 66% of snaps and Bennett on 89% (on one of the highest total snap counts for defensive linemen).
We basically had two packages for the DL last year (not accounting for rotation or injury): our base set of Clemons - Branch - Mebane - Bryant and our nickel package of Clemons - Jones/Scruggs - McDonald - Irvin.
Right now our base package would be Avril/Bennett - [ ? ] - Mebane - Bryant (I don't expect Avril to play as many snaps as Clemons did, and we'll probably see Bennett as a "heavy" LEO on clear rushing downs) and the nickel would go Avril - Bennett - [ ? ] - Irvin. I also think we'll try to decrease Red's snaps (keeping him fresher and more effective later in the season) and spend more time in an orthodox 4-3 with Avril - [ ? ] - Mebane - Bennett.
So unless Clemons makes an Adrian Peterson-like recovery (notice I haven't projected anything from him), we can pretty easily project Avril and Bennett to play a similar number of snaps as last year: Avril takes the majority of Clemons' LEO snaps, while Bennett takes most of the Jones/Scruggs role plus some snaps at each of LEO and traditional LDE (resting Bryant).
The remaining holes are clear: 3-tech in the base sets and 1-tech in the nickel. The answers for those may come from guys on the roster (Scruggs, Howard, McDonald?), veteran FA (Branch re-signing for cheap?), or the draft (does Sylvester Williams fall to 56?).
One thing to note is that besides being the heavy run-stuffing 3-tech in our base set, Branch provided insurance at the 1- (Mebane) and 5-tech (Bryant). Right now it seems that an injury to Red would have to mean transitioning fully to an orthodox 4-3 with Bennett at LDE, while an injury to Mebane means...McDonald and Howard split time at the 1-tech? So given the system we like to run, backups (or a single guy who can plug both holes) there are another spot to fill. It's a little bit hard to believe from where we started free agency, but we're actually deep with pass rushers (especially if Clemons returns sooner rather than later) and shallow with run stuffers (only Mebane and Bryant with no real backups).
Given all that, my ideal rest of free agency/draft is to bring Branch back on a 1-2 year deal (giving us a guy who knows the system and can play any of the 3-, 1-, or 5-tech in our base set) and then draft his eventual successor (guy who has the 300lb+ size to play the run in our base defense but who's a little bit more disruptive of a passrusher on early downs, and who could maybe also be the nickel 1-tech) somewhere in rounds 2-4.
Wild guess at snap counts (because I know you care what I think...)?
LEO: Avril 65% Bennett 20% Irvin 15%
3-tech: Branch (or other cheap veteran FA) 40% Bennett 40% Young guys (Scruggs/Howard/McDonald/Draft pick...whoever steps up out of the group) 20%
1-tech: Mebane 65% Young guys 35%
Other DE (5-tech/traditional LDE/nickel rusher): Bryant 50% Irvin 30% [Irvin plays 45% of snaps total] Bennett 20% [Bennett plays 80% of snaps total]