Monthly schedule sum letter values

So
I have to create a monthly work schedule where the work hours and work time vary
So I created a spreadsheet "legend" where in 1 column are letters and column next to it has hour values
and other spreadsheet(s) are where those letters should be used and summed to keep count when doing next month schedule that how much all the workers has hours planned
I have tryd to counting, vlookup, suming.. but either some mistakes in my trys or im on a wrong path to do that.

Iv included a file with the legend and one spreadsheet =)

Thanks in advance.. Mamm0th.