Hello MrJingles,
The sad answer is, unfortunately not.
The most you can hope to achieve is to maybe remove the plastic bezels from your monitors so as to create a minimal bezel size.
If you wish to have your cross-hair located in the centre of the middle bottom screen then you will need to run the FPS in 3x1 mode rather than 3x2.
This is 1 reason why some users prefer to use 5x1 in portrait as this provides a non bezel effected cross-hair.
3x2 has not proven to be a popular choice among gamers, however it is fairly popular with businesses wishing to create video walls for playing media, rather than gaming on.
While I am writing this an idea has popped into my head with regards to Eyefinity now supporting a mix monitor resolutions to be used.
If the game places the reticle at the half way point between the top and bottom of the render, then in theory if one was to reduce the number of pixels (height) in the top row of monitors, then the reticle should be aligned to the middle of top and bottom, this would drag the reticle below the bezel line.
Example... (with very crude maths)
top row 10
bottom row 10
total = 20
total /2 = 10 (exactly where the bezel is)
If however...
top row 6
bottom row 10
total = 16
total /2 = 8 (10 is the top of the bottom monitor, so position 8 would be below the bezel).
This would assume you can set all monitors on the bottom row at 1080p and the monitors in the top row at say 1600:900, this may introduce black bars, it may screw with the correct fov/positioning of rendered content, as I say this is an untested idea/solution.
In theory, it might just possibly work, although results could vary and this ultimately depends on how well the AMD drivers can support this but it might be worth investigating, perhaps you can share your findings with us.
Not sure what else to suggest at this time.
I do not have 6 monitors connected at this time to be able to try this, and this is a rather long shot of an idea, untested.
Regards,
Delphium