I think Badger is touching on the first thing that jumps into my head on this topic and it's not something that Shane mentioned in the video - "Economy and Logistics."
- How expensive (in dollars, materials and time/labour) is it to build.
- How easy/quick can I transport the tank to where it is needed.
- How easy is it to maintain in the field; parts/fuel/ammo etc.
The Germans loved to experiment and came up with some great designs but shot themselves in the foot by having a million and one (OK I rounded up
) different variants operating in the field, many with different parts and gun calibers etc. Great for us wargamers but a nightmare for any commanding officer in the field on a real battlefield trying to prepare for an operation. The Americans did have the same high degree of experimental designs but to their credit didn't implement most of them because they were (among other things) keenly aware of the problems above, and the fact they had to get them across an ocean as well. This whole issue in a case study is the timing of the Kursk offensive. Originally planned for May it was constantly put back until July which allowed the Soviets to dig in extensively and reinforce the region. The delay was all down to a comparative handful of new wonder weapons to reach the front to take part - the Panther, Tiger I and Ferdinand. All of which hit major problems, even before they reached the front in some cases, and it could be argued had a limited impact.
Granted we have 20/20 hindsight but...
Germans - I would have stopped development at the Panther and focused solely on effectively building mass numbers of these. When I know by 1943 that I'm being out-produced by my opponents and will be on a defensive posture for the foreseeable future I would want to try at least to keep up with an effective design that could take on 9/10 of the opponents it's likely to face on the battlefield.
Americans - They got it down mostly right with the Sherman but agree their Generals should have adopted the 76mm or 17pounder Firefly sooner than they did.
Russians - Perhaps ideologically and with their existing doctrine they always had build something = build lots of something. To their credit they let go of their ineffective tank designs very quickly compared to some other countries in favour of building more T-34's and KV1s etc.
British - Well they participated.
The fact they adopted the Sherman as their main tank instead of their own troubled designs shows they were at least honest with themselves going into the second half of the war. They also realised with the combined operations with the Americans that using the same equipment would help in the long run.
Italians - Well they looked pretty.