Of course, many other factors are probably involved in any kind of practical estimation. Densities of turbines and wind farms are probably important. There's also the aspect of birds learning to avoid these turbines over time, and the question of whether we can/would do something to make these turbines easier for birds to avoid. For the latter, we have a lot of creative solutions recently - https://www.rechargenews.com/wind/wind-farm-eagle-deaths-cut..., https://vortexbladeless.com/technology/, https://tethys.pnnl.gov/sites/default/files/publications/May....
Of course, many other factors are probably involved in any kind of practical estimation. Densities of turbines and wind farms are probably important. There's also the aspect of birds learning to avoid these turbines over time, and the question of whether we can/would do something to make these turbines easier for birds to avoid. For the latter, we have a lot of creative solutions recently - https://www.rechargenews.com/wind/wind-farm-eagle-deaths-cut..., https://vortexbladeless.com/technology/, https://tethys.pnnl.gov/sites/default/files/publications/May....