The RPG-22 in game, only has the 3 positions for 50m, 150m and 250m, which are fine, other than they have a very narrow field of view as you can't hold both eyes open in game as you can IRL, nor does the rear sight blur out and become larger, these are normal game limitations and totally understandable.

A way to alleviate that would be to make the sight top notch usable, the simple U notch on top of the normal aperture, and its corresponding post on the very top of the front sight.

These sights were originally intended to be used for night shooting, but there is nothing preventing you from using them in day time for a quicker acquisition, and this would bring the launcher a bit closer to the LAW which has a considerably clearer sight picture in game, and more adjustment to its range.

I am unsure about the range these sights should give, I wanna think it is 100m, but after checking several manual I can't find any mention of their range. I attached the original manual. I would check how much angle you get aiming with the top sight, then compare to the other positions, hoping that the in game model is accurate enough to give an approximation to either 50, 100 or 150m, enough to decide what to add, I would personally set it to 100m otherwise.