Speaking of arena comparisons of K3.1 and DS4.1-Flash, we're spinning one up that's more relevant than design, I think: https://agentduel.com/leaderboard
Here, DS4.1-Flash and K3.1 are basically tied, with K3.1 being slower and more expensive. Big error bars, though.
Even with error bars, DS4.1-flash is clearly an impressive model.
If your benchmark puts DS4.1-Flash at the same tier as K3 or K3.1, I'm sorry to say your benchmark is broken. It really isn't, as much as I wish it was.