When I bought my Rohloff hub, it included five small spacers that I believe were intended to allow a double crank with double crank sized bolts to use a single chainring on the crank. In other words, those spacers were about the thickness of a chainring so you could remove the chainring and use those spacers instead. I bought it in 2013 and I do not know if they still include those spacers with a new hub or not. But if they do, you could convert a double (or triple) into a single chainring crank. That said, you would have to figure out if your sherpa crank can take the desired chainring, if your crank has a 130 BCD then it probably would not work for you. I use a double crank with 110 BCD on my Nomad, I usually have a bashguard in the outer position and the chainring in the inner.
The Nomad uses a 73 mm bottom bracket, the Sherpa a 68 mm. Also, the Rohloff may have enough of a chainline difference that you might need a different length bottom bracket spindle.
I have both a Nomad and Sherpa, I like and use both bikes. Don't rule that option out either.
Regarding mixing 32 and 36 spoke wheels on the same bike, my next build (I will start building up the bike on Saturday, had the headset installed today) will have a 32 on the front and 36 in back, so that is not a problem. For a touring bike, you really can get by with 32 spokes in front. But in the back I am a firm believer in 36. (I would use more if hubs were readily available.) My Rohloff has 36 spokes, but I built that wheel, did not buy it from SJS. SJS supplied my Rohloff drilled 36 spoke rim.
...the new tiagra ten speed is a great set up every bit as good as rohloff and...
I do not concur. And if you were correct, Rohloff would go out of business.
Do you still have a light on your bike aimed at the cassette so you can check to see which sprocket your chain is on at night? Only one sprocket on a Rohloff, no need for a light.