Factual error: There is no way in hell they can carry $200,000,000 in cash (over 4,000lbs), let alone load it on the helicopter.
Suggested correction: They never did and it was never the idea. They simply didn't figure out it's not physically possible. They took as much as they could from the vault in the much more limited time they had, and never got any of it to the helicopter (except for 1 small stack) anyway.
It's true that the team was not meant to recover all the money, but they didn't know that going in. How did Ward and Peters, who seem reasonably smart, not consider the weight when planning the heist? The deal Ward believed was "get paid $50 million to recover $200 million" not "grab what you can and good luck"
I suppose it could be counted as a stupidity, but I'm not sure anyone is really aware of the weight of 200 million in cash, even reasonably smart people. Never seen it, never weighed it.