Quick answer: invest in the stats used by the class's main abilities, then add survivability or resource support when another offensive point no longer changes the route.
Start from the ability text
Use the live game tooltip to identify scaling. Old community formulas can become stale even when the general role remains correct.
Measure route outcomes
A useful breakpoint is practical: surviving an extra turn, paying for a rotation, or securing a kill before the enemy acts.
Avoid false precision
The previous version of this page published exact asymptotes without a stable official source. Those figures have been removed.