Interesting thought. You actually used to (I'm pretty sure you can't anymore) be able to set the score value for each piece in a Titan. The issue here is that it is hard to convey to the player that the rules of scoring have changed. Unfortunately, most people don't stop to read descriptions, so it would require some obvious cue in-level that scoring has changed.

On user developed maps it's a lot about replaying it for score and you'll notice pretty quickly if the score of the bots are high or low compared to what you're used to. If not you'll notice it once you start looking for optimisation of the score.

Maybe there could be a Titan score modifier which is shown at the end of the level with the rest of the information (i.e. show Points Collected, Time Bonus, Titan Score Multiplyer, Total Score).

Then you can set a single number which should be much less complicated for players to understand and keep track of. You can make it 0.5 to make a titan give half points, or 2 for twice the number of points etc.

It means less functionality, but it gets around most issues of being too complicated I think.

You can still change the score value of the weaponry of the titans, meaning you can increase the total points value of a titan, but no lower it. I've used it to round up total score of my giants bots to make it fit the min. score value of some triggers. It's been pretty usefull for that purpose.