VERY interesting thread for me. That diagram closely resembles the 4-3 Under scheme that I'd been an advocate of for years. I think it could be an outstanding implementation. (meaning, the 4-3 elephant now vs the 4-3 Under that Pete Carroll employs... since we didn't necessarily focus on acquiring that 1-tech that we would badly need) Maybe we have that in Ian Williams or possibly 5th round pick Dial... but it's hard to say.
Anyway, I think we have the personnel to kick arse with this Seifert reincarnation... and I think Fangio's experience can pull off just about any scheme adjustment.
One note - We'd likely have to still use a DL like Ian W. or Dial as the 1-tech run stuffer in more obvious run situations against teams with power backs. RayMac has the versatility to play that LE spot on given situations where we want to mix in "more beef" inside at LDT.
I would regard Dorsey as the 3-tech backup at RDT that gives Justin more rest. Justin would still be "the man", and play most downs... but Dorsey could help keep Justin fresh and prolong his career.
Aldon would be the same (or better) beast as that RE/Elephant... with Carradine getting some reps to help Aldon when needed. (then Carradine bulks up through the year and next offseason to prepare for more RDT action behind Justin)
This gives our stud ILBs more room to roam free and clean up. Brooks weighs around 255 and is in great shape... much improved athleticism. He would be an excellent SLB playing closer to the line. He stuffs the run and funnels runners back inside well already, and is quicker now to handle the short zones in the pass game. (no, we don't want him running deep with TEs and RBs on seam or wheel routes though) He also has lots of looks running the arc to attack QBs.
This Seifert scheme... just like the Carroll scheme... makes it VERY hard for offenses to block the right side of the line... which happens to possess our 2 best pass rush terrors in Justin and Aldon.