About the speed: actually DB's rules threw me: the road speed should be
Max speed: 15mph like the Matilda - you're quite right ??: .
'24' is the equivalent in kms. It surprised me, though actually the Valentine III did have a weaker AEC diesel engine: 131hp compared with the Matilda's 2 X 95hp or 97 hp. The Mk IV produced 138hp I think, but I don't supppose that's going to make much difference when a Panzer IV is producing 300hp.
The question of the off-road speed is always difficult: DB classes a Tiger I as 'slow' on road even though it's speed was 24mph. Perhaps he was calculating a good off-road speed for the Valentine becuase of it's weight difference: 38,000lbs-odd verses the Matilda's nearly 60,000lbs. But still: a Matilda only dropped 2.5mph off-road so I can't see how the Valentine can significantly top that - in fact I've now seen 8mph quoted as a Valentine off-road speed - that's slightly slower than the Matilda.
So, keep as is, I should. What rules do you play with, Alex?