I read Hrothgar's post as humorous. Is this really a thing you do at your table?
Yes. What's the point in having scores if you're only going to use them when they're inferior to the "scores" of the player? We would ask for a strength check if a character were to attempt to move a boulder, unless their strength was so high that victory was without question. Why would we
not ask for an intelligence check if there is a question of the character's ability to plan a battle or engineer a building? If their intelligence is high enough for success to happen without question, then there's no need to roll. But there's a very valid reason why folks with an int of 6 are not strategists, engineers or wizards.
On top of that, it's unfair to the rest of the party. You pick your stats because you want to be good at the things those stats imply. Hitting things. Enduring things. Avoiding things. Thinking things. Knowing things. Impressing people. In a general sense, that's what these stats tell the game you're good at. You picked them, hopefully, because you want your character to be good at those things and not simply because you were power-gaming. Even if you did, if your stats are telling the game you're not good at thinking, then allowing a character to plan a battle as though they were devalues the stat. Might as well be a 20, or a 0. It has no meaning and it makes other players, who
want to be good at those things feel like their choices were meaningless. Because they are. Because in ignoring the stats you have stripped them of meaning.
If the players want to OOC figure out a plan and then in-game have the smart guy present it to the King, I'm 100% fine with that. That's what the player/character dichotomy is good for. That's why I encourage people to make well-rounded characters.
So yes, to sum it up, using your brainmeats is no different than using your armmeats. If the outcome is in doubt due to your stats in those areas, I will make you roll to see if you had a moment of brilliance and can convey your Player thoughts appropriately through your character's stats.