He never said that his Muggle allies were killing themselves; the blood sacrifice mentioned could easily be from those who were killed in the Nazi extermination camps.
Is there a difference, from the magical point of view, between Muggle allies slaughtering each other to fuel Grindelwald, and slaughtering non-allied Muggles to fuel Grindelwald?
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.
Update: Discussion has moved on to a new thread.
The hiatus is over with today's publication of chapter 73, and the previous thread is approaching the 500-comment threshold, so let's start a new Harry Potter and the Methods of Rationality discussion thread. This is the place to discuss Eliezer Yudkowsky's Harry Potter fanfic and anything related to it.
The first 5 discussion threads are on the main page under the harry_potter tag. Threads 6 and on (including this one) are in the discussion section using its separate tag system. Also: one, two, three, four, five, six, seven. The fanfiction.net author page is the central location for information about updates and links to HPMOR-related goodies, and AdeleneDawner has kept an archive of Author's Notes.
As a reminder, it's often useful to start your comment by indicating which chapter you are commenting on.
Spoiler Warning: this thread is full of spoilers. With few exceptions, spoilers for MOR and canon are fair game to post, without warning or rot13. More specifically: