Exactly right. It seems based on the unrealistic assumption that someone will have a long-enough tenure at your company for the two lines to cross. It is far

Exactly right. It seems based on the unrealistic assumption that someone will have a long-enough tenure at your company for the two lines to cross. It is far more likely that they will jump ship for a better baseline assumption (and the base salary that goes with it) than that they will stick around for you to see the two lines cross. When discussing lifelong learning and skill growth it is also worth being honest in the description of the lines. Few have a constant upward slope, they usually plateau for a bit and can even turn negative if you get stuck in an obsolete skill set. Just because someone's 'slope' looks positive now does not mean that will continue.