Does defense matter?

I'm trying to settle a question/debate that has come up in my online sim league. My teams are performing horribly on defense despite reasonably good talent. But what I'm hearing is advice from more experienced players like, don't bother with base defense (4-3 / 3-4), you should be using at least 80% 3-3-5 and dime. Quote from one player who's a two-time champion: "I'd say quarter is probably my most common formation right now and we stop the run pretty well."
Read: The quarter defense stops the run. That just plain should not work. Another experienced player told me quite plainly (and I quote) "real football strategy isn't going to help a lot." I was absolutely FLOORED at those statements! I was also told very plainly that the coach defensive playbooks are useless and that I'll "always be in the bottom of the league" unless I use custom playbooks. I already do on offense but defense isn't my forte so I've tended to let the CPU/coach handle that. No no no, I'm told. You will be at the bottom of the league if you don't customize. That just seems wrong to me. I can understand that a truly dominant world-class player will need custom plays and playbooks but to have to do so just to avoid being in the basement tells me there's some flaw with the game's AI or logic.
So all the football I've been watching for 35 years, all the strategy I've picked up from watching pro coaches and players for 35 years is moot in this game? From the discussion it basically seems that the defense in the game is not realistic and if I'm getting advice to go almost exclusively nickel (NFL teams I looked up average about 27% in base formations). While it does make sense that base defenses are easier to pass on, this does seem extreme. It just seems to me that the advice I'm getting on how to set up my defensive playbook and game plan, should not work. In a different league I noticed even the best defensive teams have few defensive players above 65 OVR.
I understand the dev team is limited and programming AI to act like real life is extremely difficult. The Madden game is 30+ years old with a huge team of programmers and practically unlimited budget and they can't even get it to work. This game is despite its issues still has a very bright future ahead and is ahead of Madden in many respects. I've already purchased pre-access for the College game and plan to for Pro 24. But I'll be honest it does suck a LITTLE of the enjoyment out if I'm feeling like I'm learning how to beat the game rather than play defense. But I'd like to ask a few questions from the devs: Do you think this is a fair assessment? What is the general attitude is in terms of how much priority is given to realism. How much does the game's internal AI try to replicate real situations? For example, if I run successfully does that truly open up the pass? Should 4-3 at least work against the run? What do you say to the advice I'm getting that real football logic doesn't really matter?

So all the football I've been watching for 35 years, all the strategy I've picked up from watching pro coaches and players for 35 years is moot in this game? From the discussion it basically seems that the defense in the game is not realistic and if I'm getting advice to go almost exclusively nickel (NFL teams I looked up average about 27% in base formations). While it does make sense that base defenses are easier to pass on, this does seem extreme. It just seems to me that the advice I'm getting on how to set up my defensive playbook and game plan, should not work. In a different league I noticed even the best defensive teams have few defensive players above 65 OVR.
I understand the dev team is limited and programming AI to act like real life is extremely difficult. The Madden game is 30+ years old with a huge team of programmers and practically unlimited budget and they can't even get it to work. This game is despite its issues still has a very bright future ahead and is ahead of Madden in many respects. I've already purchased pre-access for the College game and plan to for Pro 24. But I'll be honest it does suck a LITTLE of the enjoyment out if I'm feeling like I'm learning how to beat the game rather than play defense. But I'd like to ask a few questions from the devs: Do you think this is a fair assessment? What is the general attitude is in terms of how much priority is given to realism. How much does the game's internal AI try to replicate real situations? For example, if I run successfully does that truly open up the pass? Should 4-3 at least work against the run? What do you say to the advice I'm getting that real football logic doesn't really matter?