How to understand evacuation levels?

I do not understand the Manatee county evacuation levels.

They are defined from A (red) to E (purple), with the A evacuation level areas being right on the coast, and E evacuation level areas being more inland. So it seems A is a more severely impacted area, maybe. It also says "Level A residents will be evacuated first", so again this suggests A level evacuation areas will be more severely impacted.

But the potential surge inundation is only 11 feet for A and 33 feet for E, and Evacuation Level A is considered to be "lower" than Evacuation Level E. So this confuses me.

Can anyone explain which evacuation level area is the more dangerous and is to be evacuated more urgently?