The mission always drives the gear, not the other way around. If you want to train for carry, use carry gear. If you want to do combat/gunfighter training, equip appropriately.
There is a difference between carry training and tactical training, though. If you use a "carry" setup at a pistol course, that works. If you use the same setup for a rifle course, it generally does not. I don't know of a single civilian person who will be using their rifle in the manner that most tactical training is done. The extent will generally be home defense. Inasmuch, you don't need to develop some type of gear setup for "real world use" because the reality of it for most civilians would then require them to show up to class with a bathrobe, slippers and cell phone. Instead, the way to look at it is training consistent with the whole "well regulated militia" part of the 2nd Amendment where a militia could constitutionally be called upon to defend the homeland. Something to that effect would then require the user to adapt their gear setup to the mission at hand, and a combat setup would be more appropriate.
For most instances involving pistol training where you would elect to NOT use a carry setup, a war belt setup works quite well and offers a minimalist approach that will also be very comfortable. If you take a 2, 3, 4 or 5 day pistol course, and you do not regularly wear a belt laden with a pistol and multiple magazines all day, every day, week in and week out, you will likely start to feel discomfort from going hard for 8-10hrs per day for multiple days. If you knuckle through it, rock on. War belts are a way to wear the gear more comfortably with less fatigue and discomfort than with a conventional pants belt setup. It's also good for distributing weight better, which is better for your back and hips.
If you are going to run armor or chest rigs for rifle use, using a carry approach may actually cause gear interference issues. I would certainly recommend training like you intend to fight. However, a war belt can be setup the same way as your normal belt setup and still give you the same benefit, but with more comfort. My war belt is a VTAC Brokos belt with an HSGI Cobra riggers belt, and I have it setup nearly identical to my duty belt. There is enough commonality between setups that I can train with my warbelt setup and it directly translates over to being proficient with my duty belt, without having to go to training with an uncomfortable duty belt that will be getting very dirty and abused.
War belts can support pistol training, as well as some light rifle training. I know that some people really like to stick with war belts for rifle courses, but when you start taking courses like TRICON CC2 course where you need 5 magazines on your person, sticking that all on a belt just doesn't work. A fully loaded 30rd AR15 magazine weights in at 1lb. Add in 4-5 of those, then add 2-3 pistol mags at 8-10oz each. Add in about 2-3 lbs for the holster, warbelt and retainer belt, as well as the magazine pouches. Add another 2-3lbs for a loaded pistol, and then add in another pound for miscellaneous whatever. You now have 10-12lbs or more on your hips. If you can move half of this weight to your chest, do it.
Some people opt to run chest rigs, plate carriers or armor carriers. If you have no specific need for armor, I would opt for a chest rig/harness for rifle shooting. The best rig I've found is the Mayflower R&C UW Chest Rig, which is phenomenal and can do almost everything you'd ever need. Other than that, there are excellent options from FirstSpear, VTAC, BlueForceGear, Esstac and SKD PIG, among a few others.