I told ya I didn't test it...
I was just explaining the concept that Toxaris mentioned you have to have the individual images inside a single SVG wrapper...not multiple SVG wrappers.
However, If you add a definition of the X and Y coordinate to each of the images you can place them however you want within the same wrapper. Notice you also have to increase the size of the viewbox to accomodate the height of all 3 images.
Code:
<body>
<div style="text-align: center; padding: 0pt; margin: 0pt;">
<svg xmlns="http://www.w3.org/2000/svg" height="100%"
preserveAspectRatio="xMidYMin meet" version="1.1"
viewBox="0 0 600 600"
width="100%" xmlns:xlink="http://www.w3.org/1999/xlink">
<image height="192" width="600" x="0" y="0" xlink:href="../Images/image1.gif" />
<image height="192" width="600" x="0" y="200" xlink:href="../Images/image2.gif" />
<image height="192" width="600" x="0" y="400" xlink:href="../Images/image3.gif" />
</svg>
</div>
</body>