This is how you balance and fix conditions

1- No more intensity stacking from a SINGLE source.

2- All conditions are duration stacking from a SINGLE source and intensity from MULTIPLE sources.

3- MULTIPLE players can add the same condition on the same target, but 1 stack each.

4- Re balance condition application.

5- Re balance condition duration.

6- Re balance expected condition damage.

Presto, you have a linear model for condition damage and application. Which incidentally is what they were always supposed to be.