I have a suggestion about the Hafthohlladung. Maybe it can be like a mine. Yes, this is not the intended purpose. But maybe a soldier could bury it and when a vehicle comes it sticks to the hull and then boom. It could act as an AT mine, like the PE AT mine only maybe alittle differnet like muni cost or damage. And the PE AT mine is doctrinal while the Hafthohlladung would be able to be used by regular infantry as earlier proposed. A high muni cost would also reduce the chance of "spamming" it.
And I think the sherman is so tough due to balance