No, it is not included in every other strategy game, lol.
It is included in most console-focused, hardly strategic games for kids with the attention span of a goldfish. However, in some games, it makes kind of sense due to, say, advanced technology - Battletech being one - I have no problem there as 'I am inside of a massive machine with advanced computing capabilities' equally, me sitting with a firearm in the bushes - I can't tell my chance to hit. Simples.
Neither of the reasons you describe is suitable or needed - if you played JA2, you would know your merc would tell you they can't hit something. Also, you would see when the firearm is outside of the effective range. The beauty of JA2 is in the fact that you know your merc. You know which one can hit from a distance and which one will never do it. You know you need to get your camouflage kit, NV, and sneaky guys to do specific ops. You don't need stupid % to tell you that... and if you do need it - this game is not for you. Move on.