I haven't subscribed to the near identical trainer mantra in well over a decade. While I've retired from serious competition, I did put in a few decades where competition was a several times a month thing for me.
The marksmanship basics are not indelibly bound to the idea that the rifle defines the skill. To do so handicaps the marksman to only being proficient when the equipment fits within a narrow range of variations.
That is the diametric opposite of what a proficient marksman should be; a shooter who can pick up any firearm and deliver its accuracy potential, or be at least able to define the flaws it contains which prevent such performance.
Does that mean I do not have 'identical rifles"? It does not.
I have pairs of rifles that differ only in chambering, or even not at all. But I own no trainer rifles. Saying I own trainer rifles is like saying I own sniper rifles. The rifle is defined in terms of its use, not in terms of some marketing strategy. I have no use for a sniper rifle because I am not, never have been, and never will be a sniper. All of my rifles are accurate enough to serve such a purpose, but without that purpose they will never be such. It's like calling every gun owner who owns an accurate rifle a sniper. As much as the gun haters may wish, they cannot make that so by simply saying it.
The same applies to trainer rifles
One pair of my rifles are bolt rifles chambered in .223 and .308. They are identical because both shoot a similar course. The difference is that the .223 is intended to shoot the 600yd MR F T/R Course, and the .308 shoots a 1000yd LR F T/R Course.
When I shoot; I do so with a single purpose, to defeat the target. Each and every time, each and every marksmanship skill is called into use. For my intents and purposes there is no, zero, difference in the context of the shooting. Defeating the target is the object of every shot, score is just a consequence, which may be useful in competition, but really, is not necessary to the task regardless of whether or not a score is the object.
So by my definition, there is no such thing as training. Every shot is done to the same standard, and has the same importance. Every shot is done for a purpose, and the manner in which it is done is training for every other subsequent shot. The two purposes are inseparable.
I also have a pair of totally identical long barreled 223 AR's, complete with high resolution scopes. They are for the single purpose of private one on one competition. It is Training? Sure. Is it Competition? Sure? For my intentions, and for all other purposes, the two are one and the same.
There s absolutely no reason why it can't be the same for the other situations. Shooting is about hitting targets, no more, no less. To place a distinction between training and competition is to define a difference where none exists, as far as the actual process is concerned.
To accept such a difference means that the shooter has some erroneous concepts that one does the two things differently. They should not.
Greg