Yes Slide Rule was an interesting read - one of the 'differences' between the 2 ships was that the R101 had the Airship equivalent of 'power steering' (another heavy 'add on') but the R100 was completely 'manual' - it was one of the things that worried the R100 team in case they had done their calculations wrong.But on flight test they found that they could quite easily get a few degrees of rudder 'on' and as the ship started to turn they could get a few more degrees of rudder on if required.
The R100 design team did a lot of 'worrying' over the design differences and whether they had 'got it wrong'
I am afraid there is no doubt that the R101 was badly designed with lots of muddled thinking going on - meaning it was grossly overweight which then begat more 'bodging' - the relative situation was probably compounded when the R100 had a good trip across the 'Pond' which probably sealed the fate of the R101 in that the 101 was in effect 'forced' to go on the (India ?) trip because of the R100 success in the USA.