From the Brushbeater forum:

My training rifle is a box-stock Colt w/ 16” stainless barrel, Magpul furniture, Blue Force sling, and Magpul iron sights w/ Blitzkrieg fiber optic front post insert. Yes, I know it’s 2021 and optics and this and that. I completely agree (see advance rifle below). I’m a firm believer in learning the basics first, than adding on all the modern do dads.
My advance rifle, for after I get good w/ basics, is Aero upper and lower, Wilson Combat BCG and 18” stainless barrel, Magpul furniture, Blue Force sling, Vortex Viper LPVO in QD mount, and Magpul BUIS.

This is an interesting post. Not knocking the concept at all, but I will offer a bit of a rebuttal.
Are you a handgun shooter? Handgun shooters know that, generally speaking, we pick one platform and stay with it. Training, be it dry fire, live fire, and movement, all builds mastery through repetition and that’s only achieved through sameness across the board. Your training rifle should be your go-to-war rifle. When you pick that weapon up, it should be exactly what you expect- no surprises. You know how it feels when its running correctly and diagnosing issues on the fly becomes much simpler.
In the Carbine Classes I will normally have 2-3 students’ weapons experience repeated malfunctions. This comes from a lot of sources, usually magazine issues, but even still, I can diagnose it quickly and effectively. This is because of the sheer number of rounds I’ve got and the time on the range with the AR platform, but even still it amazes some. I don’t think its amazing at all. I think its vital knowledge to wholly understand one’s weapon.
Where I’m going with this is that I have many ARs, but only one I use in class and that’s the same one I’ll be carrying into combat should the need arise. (The same with the AK). I have many thousands of rounds down the tube, I know exactly how the carbine feels when the mag is about to run dry simply due to the sound the buffer spring is making (the impulse feels different as well) and can immediately tell if I’ve got a malfunction by the same.
Basically all of my weapons are set up the same with minor differences based on the role they play. Free floated, sling mount in the same place, optics and enablers mounted in the same places. This creates muscle memory so that I’m not changing up what I’m doing from gun to gun and having to re-familiarize myself with a whole new weapon.
My advice is to set both of your weapons up the exact same. There’s no reason to handicap one with irons (and yes, it is a handicap). You’re actually not doing yourself any real world favors because optics take time to learn and build that memory of use as well. It sounds like you’ve got quality components, so you owe it to yourself to make the most out of both.