And there were tanks! Not terribly good tanks, it has to be said, but tanks none the less.
(Sorry to see no TOG as yet, but you can't have everything)
Interesting battle you've got shaping up - Martell versus Hobart, speed versus armour, theory versus practice, maybe style versus substance? Hobart has a fight on his hands - Martell's bottle-rocket mini-tanks are likely to appeal to the cavalry, not to mention the Treasury.
Either your A13 spec was different to OTL, or Martell stretched it to the limit to come up with a two-man design. I've always thought the historical A13 was about the best of the early cruiser designs - decent performance, passable armour, proper crew layout and no silly mini-turrets. (Mini-turrets are one of those nice theoretical ideas that flat-out do not work in practice. The real case against them isn't shot-traps, it's that they take up way too much space, weight and man-power for what they offer. The 14-ton A9 had a crew of six!)
The A10 is - or should be - conclusive evidence against the commercial-engine policy. All the performance of a Matilda with less than half the armour; it's a measure of the Army's desperation for something bigger than a MkVI that any were produced at all. A pity, really, since it had a decent layout and with a proper powertrain could have been a step away from the tinfoil cruisers. (Incidentally, unlike pretty much everything else, it apparently had a reputation for reliability, and its chassis and suspension were passed on to the Valentine, which likewise had reliability as about its only virtue.)
Interesting to see what comes of the A14 - can it walk the line between big, slow and undergunned, and big, fast and flimsy?
One thing I'll toss in. Apparently sometime around 1938 the Army ordered an LT38 (later and better known as the Pz38(t)) for evaluation, but rejected it on the grounds that the ride was poor and the crew compartment was too cramped. (The Germans showed what they thought of that objection by rearranging it to fit a fourth crewman). Comparing it to the (larger) cruisers, it has very similar armament and protection, a bit less off-road speed, but a very very solid and reliable suspension and drivetrain. Something to think about when you get tired of replacing thrown tracks?
On to Spain!