Fleabag VS. Mutt is an old flash game for children. Nowadays, it also has app on Android.
You can try to play it.
We consider that Fleabag and Mutt are on the same height and they have a distance D. The wind resistance is F (If F < 0, the wind is from Mutt to Fleabag, or it will be from Fleabag to Mutt). Fleabag or Mutt will give their hidden weapon an initial velocity (both horizontal and vertical).
Both on horizontal side and vertical side, we can consider the weapon is on a uniformly accelerated motion on its two directions and G is 9.8.
Here are two formulas:
a = F / m
s = v0t + (1/2)(at^2)
If the weapon hit the area that the distance to another one is less than 2.0, we consider it hit another one.
Fleabag 1.0 1.0 1.0 1.0 4.9