I think the quote that the op made from Hess' book concerning the Jehovah's Witness women needs context. There is much about the happenings within the Society, their shifts in doctrine and power struggles that need to be understood to be able to better understand the position that the women took.
Firstly, one of the things that is badly misrepresented by the Society is that they were 'one religion' during WW2 when they were not. There were two distinct divisions within Germany of their religion of the time. When you read of accounts of 'the Jehovah's witnesses' and accounts of Bible Students, we have learned to lump them both together and use the terms interchangedly, quite simply because the Watchtower Society does - they claim 'ownership' of the Bible Student statistics during the Second World War when they are not entitled to them. The Bible Students weren't part of the Watchtower Society at the outbreak of WW2. And, the differing accounts that have been recorded historically reflect the internal politics of the Watchtower Society and how they were struggling for power within a political maelstorm. WW2 actually served to 'divide the flock' for them - right inside of Nazi Germany.
To back up a bit, the tumultous years following Charles Russell's death in 1916 saw many things happen within the power base of the Society, and with those changes came doctrinal changes that aligned them with political ideology as well. The Society was notorious for sticking their nose into world politics.
This began with Russell's very public stand in support of a Zionist State of Israel - he even published a Yiddish newsletter at one time in addition to many travels abroad to promote his notion of a Zionist State. Russell's involvement in the promotion of Zionist Israel had much support within the Society after his death and the shift in the doctrine concerning that position was consistent with who stayed with the Society and who stayed with the Bible Students. This is critical to understand when contemplating the history of the Watchtower involvement in WW2.
Those who backed Rutherford and his ruthless struggle for the power to control the coffers of the Watchtower Society were those who also held his political views - the same views as the people who financed Rutherford's Beth Sarim project in California.
Those who didn't - the ones who still held to the views of Russell and who he was connected to politcally, like Hudgings, for example, were the Bible Students.
The Watchtower religion within Germany (and elsewhere) was fractured - those who followed Rutherford's new theology/politics and those who didn't. Two very distinct groups.
To back up again for a bit - back to WW1, there is something that the Society has swept uder the rug. And that is the matter of what happened in Germany with the Bible Students.
The Bible Students in Germany, during WW1, joined the ranks of the German Army. They fought, and died, as soldiers on the front lines for Germany. Charles Russell, in the Watchtower magazine, gave his support for those Bible Students and even encouraged the women Bible Students to keep the men on the front line well fed with encouraging letters and, of course, Watchtower material.
Now. Hitler. He also served at the front for Germany in WW1. Hitler was first and foremost and always a soldier. It was one of his reasons for his contempt of the intellectual class - he saw them as pansies and parasites of society because they didn't fight during the war. Hitler was patriotic to the extreme and was contemptuous of anyone who he saw as impeding Germany or contributing to Germany's defeat in WW1. And, one thing that really annoyed him was the evangelists that had served at the front lines in that first war. He saw the evangelist material as demoralizing the troops and that those men had harmed Germany's position rather than helped. And that is why he had such extreme hatred for the Bible Students, along with the Seventh Day Adventists and Baptists.
But, those Bible Students who still supported Hudgings and that faction were no longer Rutherford's political allies and that was what Rutherford and Knorr tried so hard to correct.
And you do see a difference during WW2 in how the 'JWs' were treated - some accounts are horrific and yet, on the other hand, many accounts reveal the 'better' treatment of JW concientious objectors. Wewelsburg Castle priviledges, along with positions of trust within Himmler's financial arm of the SS, and other placements of service to the SS, reveal another side to what really happened during WW2 concerning the Jehovah's Witnesses.
The Watchtower Society, in their attempts at revisionist history, have shamelessly exploited their falsehoods concerning what was really happening in Germany.