Well, you could just do the first 5 levels of values up to 30% and 24% respectively. In that case, you'd probably want to half the value of existing ship bonuses (both positive and negative ones) to make them more balanced with the rest of the mod.
I'd personally scrap combined "sensor array" components now, and replace them with a set of two combat and ecm components at half their normal size instead. It is too difficult to get them to work without stacking. You could still offer a combined sensor array that merged combat and muliplex, or ecm and multiplex, etc, just not combat and ecm together.
