Sorry, but I still only have a very hazy idea of what you're trying to say! It seems like a very slippery argument and I'm not sure that it holds water. Could you make it more rigorous?

The first claim is that each black square must be bombed before its adjacent white squares. I take this to mean that if S is a guaranteed-tank-destroying sequence of firing coordinates, and b is some particular black square with w some particular neighbor of b, then the first occurence of b in S must fall before the last occurence of w. (That is, b may be targeted after w as many times as one pleases, as long as w is targeted at least once after the first targeting of b.)

The next statement is: "bombing all blacks and then all whites is the same as bombing them in some other pattern that meets the same requirements and outputs the same number(for instance, bombing all whites in a row then bombing all blacks in a row.)" And here I'm completely lost: What does it mean, precisely, for two firing sequences to be "the same"? Does it mean that either they both are guaranteed to kill the tank or they both are not, and that they are also of the same length?~