If your gantry positioning and overlap are truly repeatable, you may not need panorama stitching at all — simple tiling/compositing is enough. In that case, tools like ImageMagick (using montage) or even IrfanView’s panorama function can assemble equal-sized images into a fixed grid with zero spacing.

If there is any small variation in position from shot to shot, then panorama software is the better choice because it can align overlapping images automatically. Hugin is a reasonable option for that kind of workflow.

There are also gigapixel-oriented tools, such as software used with GigaPan systems, that may suit automated multi-image capture and stitching.

So the practical split is:

• Consistent grid, no alignment needed: use a tiling tool.
• Small positional differences that need correction: use panorama stitching software.

Google Maps-style viewing is typically based on pre-rendered tiles for display, but the source imagery usually still has to be aligned and assembled first.