It's going to be pretty tricky to balance mathematically. You're going to have to trust your gut to a large degree because only you will have the level of campaign-specific knowledge to decide that.
Example: Which stat is more important STR, DEX or INT.
STR: Really depends on how often strength-based weapons are used and heavy objects are encountered. If there are a host of monsters with str-based entangles then the value goes up. If everyone is using magic wands and laser rifles it goes down.
DEX: How important is it to go first to win the fights? Is the most important aspect of combat offense, defense or resource management?
INT: Are the most powerful players wizards? Are there INT based devices and challenges that come up frequently?
I am interested to watch this thread though.