而在维克斯的设计中，戴主任则指出，他们完全没有抓住采用前置主炮的重点：
In the Vickers designs, although they have placed the funnels aft, the importance of having the boilers themselves aft and away from the magazines has been entirely missed, there being 3 boiler rooms with magazines in close proximity to each of them. This is a very objectionable feature, and Messrs. Vickers have apparently missed entirely the importance of having the boiler rooms as well as the funnels abaft and away from the magazines. This feature also does not enable them to reduce the armour protection over the boilers rooms, as we have found it possible to do in out designs where the boiler rooms are clear of the magazines.
在维克斯的设计中，尽管他们也将烟囱布置在了舰体后部，将锅炉布置于舰体后部并远离弹药库的重要性被完全忽视了，有三个锅炉舱与弹药库相当靠近。这是一个非常需要反对的特征，而且维克斯方面显然完全没有理解将烟囱与锅炉舱布置于弹药库后方并远离弹药库的重要性。这样的特征同样没有能够使得他们得以在设计中削减锅炉舱的防护，而在我们的锅炉舱远离弹药库的设计中设计中可能做到那样。

Considered by me during September and October, and on the 1st November I gave instructions for such a design to be proceeded with, after a preliminary discussion with Controller and A.C.N.S., from which I gathered that the blind arc of fire aft was not considered to be really a disadvantage. Outline designs were got out early in November and submitted officially on 27th, the great advantages of the reduction in weight, size and cost which it was possible to make, being pointed out in my minute.
在另一段中，戴主任提到了自己提交这个设计的时间在1920年的11月，与3系列中最早的主炮前置设计，M2/3契合；而此后的3系列设计中也体现了戴主任所提到的特点：M2/3与N3均将轮机舱布置在了锅炉舱之前，以此得以有效地将锅炉与弹药库隔开；因此M与N系列设计的锅炉舱防护均能够相比于弹药库防护削减一个等级，之后的纳尔逊也是一样。

M2方案

N3方案

2楼似乎没有显示出来，只能再发一遍。

后期3系列的副炮弹药库都被丢到舰尾去了（还有一部分夹在主炮弹药库中间），大体上应该也能够相对而言减少风险。

关于G3等3系列战巡的锅炉轮机布置问题，在DKB的书中有相当有意思的表述：
The ‘Ms’ were twin-shaft ships with the engine rooms forward of the boiler rooms, presumably to reduce shaft rake.（It may have been difficult to fit in the gear boxes with the engine room aft. I designed a frigate with small blisters in the side to accommodate the corners of the large gear boxes!）Surprisingly, the more powerful, four-shaft battlecruisers (‘I 3’) had the engine rooms abaft the boilers.
尽管现在看来，DKB认为M3的轮机在前的布置是用来reduce shaft rake的看法可能是并不准确的，但DKB描述I3重新倒转布置方式时的用词很可能能够暗示，在DKB看来，I3采用M3的同样的布局，不仅在理论上是可行的，更是相对而言更为合理的。