Yup, definitely a weakness. They've made great strides on defense so far, but still work to be done before they've really got what they need in place. Run stuffing DT, an every down pass rushing force on the EDGE that doesn't need schemed up pressures like Landry, a deep coverage safety and possibly better coverage at LB are the pieces I think they still need. I say POSSIBLY better coverage at LB because I believe that if they got a legit coverage FS and a run stuffing NT then I think that would free them up to play Dugger and Peppers together as a SS and coverage LB rather than the true safety duo. I'm dreaming of a defense like:
Run Stuffing NT
Barmore in 3T
Milton WIlliams as a Jumbo DE
A pass rushing DE that can also set the edge (Landry ok for now)
Spillane at MLB
Dugger as the other "LB"
Peppers at SS
A coverage FS
Gonzo/Davis as outside CBs
MJones in slot (could use someone taller though to at least handle some matchups)
Tonga and Epps I guess fill those NT and FS roles for now, but neither are good enough IMO. Landry is ok for the DE spot for now, though his 1-on-1 pass rush chops might not get it done at a high level. So those are the 3 spots I think they still need to be searching for on defense.
It's ok though that they haven't fixed everything yet though. I think they've made good progress there. I don't think it was realistic to go from worst roster in the NFL to perfect solutions everywhere overnight. It's going to take a good draft next month and then probably another good draft/FA class next year and even the year after for this team to really be cooking with gas at the powerhouse level you need to compete for a SB. But in the meantime, I think they've made good incremental progress so far. Obviously heavy on the defensive side, still more to be done on offense.