Would a IGH drive train last longer than a derailleur drive train? Would a single sprocket + 8 speed chain + single chain wheel used in combination with a IGH last longer than a 10 speed cassette + 10 speed chain + 3x chain wheels?

Image I have 2 bicycles.

Bike 1 has a IGH Rohloff Speedhub 14 with 


16T sprocket, 
40T chainwheel and 
8 speed chain
using chain tensioner (the spring loaded one, not a tugnut). The chain tensioner is compulsory :)


Bike 2 has a 


10 speed cassette (11T-36T), 
3xchain wheels (40T,30T,22T) and 
10 speed chain.


Both drive trains are used in the same conditions and maintained and cleaned at the same time and in the same manner.

Questions


Which drive train will last longer?
What influence does the chain tensioner in the IGH setup have?


In the IGH setup, the same sprocket and chainwheel are used for every ride. 

In the 10 speed setup there are more cogs to choose from. The wear is spread out.

I think the 10 speed setup will last longer because there are more cogs.
A chain used in a single sprocket configuration should outlive a chain used in a derailleur system because it always runs straight between aligned chainring and sprocket.

A 1/8" single sprocket chain will last longer than a 3/32" derailleur chain because it has larger bearing surfaces between pins and bushings.

A cassette is likely to last longer than a single sprocket because wear is spread over multiple sprockets. Same applies for multiple chainrings on a crankset.