Suggestion: Open or closed commanders hatch

[Imp]

Cant really be done a unit cant really have 2 different states so sets of information in that way. If it could there would be many options available, limbered guns for example comes to mind. I agree the concept of risk vs reward is a good one but would tip the balance even more in the players favour against the AI.
If you really wanted I suppose you could set up a separate unit type for early tanks that would be considered unbuttoned most of the time due to having no radios & therefore having to keep the lead tank in sight & watch for flag signals but this would be very hard to represent.
Best way at the moment is to buy them as one big formation to represent lack of C & C.