The reason I'm asking is because that game uses a two dice system much like what you are suggesting.
I do not care for that system from a game-play stance because it reduces granularity between hit chances.https://www.reddit.com/r/Steel_Division/comments/6ak9j9/veterancy_and_accuracy_calculations_explained/
In addition to that and what other people have mentioned, I believe that such a system would increase the performance load on the game significantly. The current Wargame system calculates a hit simply based on (random(number) * 100 <= hit-chance + modifiers), where as Steel Division's is more like (random(num)*6 + random(num)*6 > 12 - unit accuracy value - modifiers). This may not seem like a big difference, but when you have >100 weapons on the field making hit calculations every second, as often happens in wargame, it starts to become an issue. This is probably part of the reason Steel division is a smaller scaled game. When it was released, the game would suffer performance-related crashes frequently in larger games. It was an achievement to make it to the end of a 10v10 match. This has since been fixed, but Steel Division is still more performance intensive despite being smaller in scale.
Now, I do like how Steel Division has units become more accurate for every shot they take, to simulate adjusting fire, but that could be done with a simple +10% for every shot. As for simulating ERA or active protection, that could be done with the hit calculation similar to how ECM works in game.