These aren't percents of a total - they are ratios relative to each other.
For simplicity let's say teach bar has a Min of 0 and a Max of 100. NOTE that there are no units. Bar 1 is set to 100, bar 2 is set to 70, and bar 3 is set to 0. This is absolutely valid. What this means is "for every 100 units sent to 1, send 70 units to 2 and 0 units to 3". In this case you can assign currency as the units. "For every dollar sent to 1, send 70 cents to 2 and 0 cents to 3".