I tend to see low mental stats as *permission* to play dumb (or foolish, or uncharismatic), not as a forced hindrance, though.
Ditto: Johnny Bones, a 3Ed human Ftr/Th, was Str15 Dex15 Con13 Int12 Wis8 Cha6*. He was extremely effective at his job...but he was reckless and a boorish thug & bully. He caused interparty friction- favorite victim, the scrawny Mage- and sometimes got the party in trouble. It was only the fact that he was an efficient killer and had a nose for secrets that the party kept him on.
And even as a killer, he was flawed. With the exception of knowing he needed to maneuver to get his backstabs in, his tactics were pretty much limited to charge in and kill or run for the hills.
* 4d6 drop lowest, rolled in order.