If $2$ servants $A, B$ have equal sums of capacities, they received the same set of flash drives, WLOG $1, 2, 4.$ Suppose $C$ receives the last $1$ GB flash drive. If there exists $x \in \{8, 16, 32\}$ such that $C$ does not receive a $x$ GB flash drive, then we take the two capacities $1, x.$ Else, $C$ has $1, 2, 4$ GB flash drives, and we may take $1, 8$ as the two capacities. If anyone has a proof that assumes "there are not 2 capacities..." and then proves all servants have different sums of capacities, I'd like to see it. This appears to be a problem of the form $X \lor Y$ where only one of $\overline{Y} \rightarrow X, \overline{X} \rightarrow Y$ is easy to prove.