With the fuss of brawling and kiting being brought back to the light for some peculiar reason with this coming patch, I have a slight alternative suggestion away from the factors of damage or tank. I propose simply changing the MWD module itself.
Leave the speed where it is all minor factors as they are.
However, I have two propositions to add, and basically they revolve around not being able to leave the MWD running permanently;
Give the MWD module a cooldown, and make it so that it can only be cycled once. You can do two alternative MWD lines from this. One that increases duration if you overheat the module and one that increases speed if you overheat the module.
The alternative concept is very much the same, however instead it is given the need of fuel to continue cycling. Like that of a cap charge to keep the module running before incurring a cool down. The nice bit about this concept is though a little ship will outrun a much larger one, the cargo bay of the later will eventually allow them to catch up assuming a smaller ship remains on the field.
The idea is that proper manipulation and piloting with said module on either kiting or brawling ships will decide the victor.