These are my second modifications, and result from the formula;

=MIN(MAX(((EXP(-1*(((TS*(MAX(MR/TR,1))^2)-EV)/1500)))*W),TR^0.5),W)

Looks complex, but it's not!

TS = Target Speed
MR = Missile Explosion Radius
TR = Target Radius
EV = Missile Explosion Velocity
W = Warhead Strength

The min and max statements set rules, such that;

No target can take more than the warhead's strength in damage
No target can take less than the square root of it's own sig radius in damage

Note that it also brings the sig radius and speed into a single equation. For me, this is what I was trying to achieve. Your opinion may be different!

Rockets - you only see two lines because all sigs of 25 and over give the same graph

Standards - you only see three lines because all sigs of 50 and over give the same graph

Heavies...you get the idea by now...

Cruise

Torps