6 speed auto trans from the 2WD trucks is a derivative of Aisin's AS68RC.
With a tail-shaft change (about $1500 - 2000 in parts and labour), an NV271/273 transfer case will bolt right up to the Aisin, just like it does in the Dodge Cummins trucks. The newer trucks actually have Magna-Steyr transfer cases, as New Venture Gear has gone the way of the carrier pigeon.
This leaves you with a two wheel drive low range for backing trailers and such or you can do a sold axle conversion on your 2WD FE and have a real 4WD truck with a real auto trans and a real transfer case, instead of the soccer mom mobile that MFTB has sent to the US for the last few years.
54:1 is not that great of a crawl ratio, especially not for a heavy "lumbering" truck that has a tendency to bounce and sway off road with a camper box on it's back. We are not talking about 3,000 pound competition rock buggies here. Something in the range of 125:1 to 150:1 would be an outstanding crawl ratio for technical off road work. Do you need that low of a gear all the time? Of course not, but you have six gears to choose from in your transmission, so put your real T-case in low low (5:44:1 to 11.70:1) and select the transmission gear that gives you the speed appropriate for what you are doing.
It is patently obvious that the people who designed the Canter are not serious off roaders or things like, "wet clutch transmissions" and "AWD transfer cases with no low range" would not be spec'd for this truck or any truck for that matter. They are simply out of their element.
A torque converter lock up switch would allow for engine braking to slow the truck when off roading, instead of using the wheel brakes, which again, can cause a heavy truck to shift or slide unexpectedly. This is not an option that I know of in the Canter.
To see how super low gears adds control off road, watch this video. A mate of mine has a 223:1 low range and it is amazing what his truck will crawl up or descend at IDLE with no brakes needed. Maybe Fuso will pay attention and spec the new trucks properly.
https://www.youtube.com/watch?v=CJgQKqjVoAg
no flying rocks, no bounce or sway, no spinning tires and I presume that one would not encounter an obstacle such as that in an FG.