Madden's 2-4-5 Nickel set uses a DT2 at the 3-technique position (circled in red on offense's left at an RE or RDT position) in the B gap, and DT1 (offense's right) is also used at the 3-technique position in the other B gap. In the NFL most 2-4-5 defenses actually use either one DT and one DE, or two DEs, usually not two DTs.
I noticed this design a while ago, and it's one that I initially found to be flawed; however, I only realized recently that it could also be exploited:
Because a 4-3 defense always has 4-2-5 Nickel accompanied in Madden (to my knowledge), anytime a player is used at DT2 in a 4-3 scheme they will be used in both base and 4-2-5 nickel sets.
However, in a 3-4 playbook the only places DT2 would be used are in the 4-1-6 dime and either: A. 4-2-5 Nickel sets, or B. 2-4-5 Nickel sets. Theoretically, you can do some interesting things with A, but more useful for an NFL-like experience would be B. If instead of a DT at DT2 you used a DE, then by default they will show up in 3-4 schemes at the 3-technique position as a Right End in the 2-4-5 Nickel set, with some 1-tech as well. Therefore, this design is actually incredible helpful in recreating accurate usage of certain "Nickel Pass-Rushing" DEs who tend to play in 2-4-5 Nickel sets!
Conditions
The DT2 player must not be placed at a starting position elsewhere, so it can't be a starting RE or LE. These would be "Pass-Rushing Specialists" in their team's 2-4-5 Nickel.
Who Are These People???
Here are defenses which could use 2-4-5 Nickel in Madden*. Based on their potential use as 3-technique players in nickel sets I have filled in a few possible options as far as who could be 3-tech DT2 in their respective schemes. I'd have to watch more footage to be able to more definitively say who DT2 should be:
* DEN uses only a converted Big 2-3-6 Dime set rather than 2-4-5, and NYJ and CLE use primarily 4-2-5 with some 2-4-5
ARI: Frostee Rucker (DE/DT?) [rotational 2-4-5 pass-rusher; Gunter, Mauro, and Stinson are used more in base sets by my estimation]
BAL: Brent Urban (DE) or Michael Pierce [2-4-5 situational Pass-Rusher on 3rd & Long Yardage; Pierce also shows up in 2-4-5 but as more of a "run-stopper"]
BUF: Lorenzo Alexander or Leger Douzable (DEs) [Williams is currently showing up as base RE while Alexander and Douzable show up more in subpackages]
CHI: Cornelius Washington (DE) or Jonathan Bullard [2-4-5 situational Pass-Rusher on 3rd & Long Yardage; Bullard also shows up on 3rd & Longs]
CLE: Jamie Meder (DT/DE?) [Horton uses both "4-2-5 looks" and "2-4-5 looks" with Meder; sometimes Xavier Cooper (DE) comes in as a stand-up rusher]
DEN: Billy Winn (DE) [The only non-starter who I've personally seen rotate into their Big 2-3-6 Dime on passing downs in place of either Wolfe or Crick]
GB: Julius Peppers or Mike Pennel (DEs) [whomever is not starting at LE opposite RE Mike Daniels in base sets; many of their DE/DTs and even OLBs get snaps as hand-in-the-dirt 2-4-5 pass-rushers and as DEs in base sets, it's just a matter of who is used more in base sets]]
HOU: Christian Covington or DJ Reader [Both have filled in at LE with Devon Still on IR, but I see Reader as more of a base LE with Covington coming in more in pass-rushing situations]
IND: Hassan Ridgeway (RDT/RE?) or Henry Anderson (more LE/LDT?) or Zach Kerr (DT) [Ridgeway and Anderson play 3-tech in some 2-4-5 Nickel sets]
KC: Kendall Reyes (RE) [rotational 3-tech in both base sets and 2-4-5 nickel; played as 3-technique RE behind Chris Baker in WAS]
NYJ: Steve McLendon (DT/DE?) [mostly 4-2-5/2-4-5 DT]
PIT: Ricardo Mathews (DE) [2-4-5 situational Pass-Rusher on 3rd & Long Yardage]
SD: Tenny Palepoi (DT/DE?) [him and (currently on IR) Caraun Reid are definitely used as situational 2-4-5 and "Prowl" Pass-Rushers in nickel and dime sets]
SF: DeForest Buckner or Ronald Blair (DE/DT) [2-4-5 situational Pass-Rushing DE/DTs for sure, usually Stand-Up, and I believe both do play 3-tech; it's hard to tell because they stand up so often]
TEN: Karl Klug (RE/RDT) [2-4-5 (or "Prowl") situational Pass-Rusher on 3rd & Long Yardage]
WAS: Anthony Lanier or Cullen Jenkins (DT/DE?) [Lanier is used as the situational, long yardage 2-4-5 pass-rusher, Cullen Jenkins can rotate in anytime, depends on whether you want more pass-rushing or run-stopping]