I'm sorry to criticize your playstyle Meridian, but it irks me to see you neglect to kneel to shoot, and also sometimes shoot one-handed. Girls under fire may have to be very conservative of their TUs to avoid reaction fire, but snipers and archers have typically a lot of TUs left. If a standing girl misses a 98% shot, don't blame luck, you had only one button to click to replace 98% by 112%
Also, be aware that the game engine has some bad "ideal" trajectories which actually pass through walls. If a failure is suspicious (like 2 shots at 90% miss and hit the same obstacle), there's no point in trying again the same shot : Take a voxel screenshot to study later, and move to a different tile, or kneel / stand up so you can shot with a different angle.