I know we're living in the crapsack timeline, but I didn't realize it was a crapsack made of little shit people that the Republicans sculpted like they were Play-Doh and then threw them in the sack and made screaming noises, pretending the little shit people were screaming, before declaring that sack to be their new second-in-command after Trump.
The USA was probably the most experienced in writing constitutions at the time, both on a national scale and a state scale. Even then, there wasn't that much experience compared to today and a failure of a state government could easily be corrected by the King. These were smart men trying to create a workable compromise, but they weren't perfect.
They were all educated and well connected, but I think it'd be a stretch to say they were all smart. I don't know if we have enough information to make that claim. I don't like the worship of the founding fathers. They likely weren't particularly special people, but their circumstances were.
I don't think it is hero worship to say they were smart.
We have letters of enough of them to get an idea that they understood and could debate on a wide variety of topics. They were also able to put together a surprisingly stable government at a time when this wasn't guaranteed.
They were all flawed men in their own ways, but I wouldn't call them stupid.