I'm having some trouble getting mines to work. I can make a buoy with thermal sensors and some submissiles, and I got it to release them when it saw a thermal contact, but the submissiles, which had weaker sensors, couldn't see the target and just sat on top of the mine, since that apparently counted as their initial target. Shouldn't they get targetting data from the buoy? I tried to set the engagement radius below the sub-missiles' sensor range, but it didn't seem to work; the mines fired as soon as they saw the target. Do I have to build my mine missiles with sensors as sensitive as the mine itself to function?