I would say that our scheme is more like a 2-4 Flex Nickel. I say that because we tend to use only 2 defensive tackles. I have watched Michigan only the last two games, but I noticed a lot of multiple TE sets. That is why I alluded to the true 3-4. Their passing game isn't scary. It is their running game that has me concerned.
well the groupings we use to fill out the defensive formations can change for sure. We do run a grouping that is 2DL, 2OLBs and 2 ILBs that could be viewed as a 2-4, but the alignment is a 4-2 with the 2OLBs playing like DEs. This was the grouping that it seemed like Golding would refuse to get out of, even when we'd get gashed in the run game. This year we more often run a grouping that is a 3DL, 1OLB and 2ILBs and as the season has progressed, we've played it as a 4-2 front way more often, and with way more success, than running it like a 3-3. The reason is that the 3-3 takes our best pass rushers (either Turner or Braswell) and puts them into coverage, then we usually rush one ILB. That's just not as effective as letting our OLB do what he does best and shifting the ILB out into the coverage
For reference - through the first couple of games this season (that's all I tracked), we ran the nickel D almost 87% of the time, and the dime the other 13%.
We ran the 3-1-2-5 (DL, OLB, ILB, DB) grouping 45.5% of the time, and the 2-2-2-5 41.1% of the time.
The alignment was the even front (4-2-5) with the OLBs playing more like DEs 61.76% of the time, and an odd front 3-3-5, with an OLB out in coverage 25% of the time. Our even front Dime package was used 8.82% of the time and the odd front dime (a 3-2 alignment, but sometimes we still used the 1-3-1-6 package Golding made <in>famous and one of the guys lined up as ILBs, one of whom was an OLB by trade, would typically rush so it kinda morphed into an even front rush look in the end) was used 4.41%
Net, even at the start of the year, we were an even front team between 70-75% of the time, and though I haven't tracked every play from the middle of the season on, it's been noticeable that we've shifted more toward the even front so we can let the OLBs do what they do best. Saban even referred to pushing that change to the D coaches after the first drive against UGA where we did use the odd front (with poor results) and playing even front for most of the rest of the game. We even stayed in the nickel when UGA was playing multiple TE sets