Arguably, his Muggle allies (assuming, as usual, that these are the Nazis) were indeed sacrificing themselves: they started a war which they lost, leading to their deaths (in many cases) by war, hanging, or suicide (the last including the Muggle Fuehrer himself).
However, I interpreted this as Sheaman did; sacrificing others may be less powerful, but it was a lot of others.
Arguably, his Muggle allies (assuming, as usual, that these are the Nazis) were indeed sacrificing themselves: they started a war which they lost, leading to their deaths (in many cases) by war, hanging, or suicide (the last including the Muggle Fuehrer himself).
However, I interpreted this as Sheaman did; sacrificing others may be less powerful, but it was a lot of others.