Leaves Allocation and Leaves Block

Trying to understand if both should be talking to each other or they work separately …

If i block leaves from 1-1-2017 til 30-3-2017
This means no one can book unless if part of the exception !!!

But i still need to allocate the days (22) to staff and if i select among the blocked days the system still allows me … and of course when the staff applies for leave he will currently be between the Allocated days and will not check the blocked days.

Maybe i have done the tests wrong but i have a case of blocking days from March to November and to allocate from December to February (which will work…) but what if the person allocating does not know about the Blocked days entered ?