@Raineh Daze... there's nothing in Fate/Zero by the name of Knight Tactics. That was only added in to Grand Order so Diarmuid had the necessary three skills, the entire concept of exploiting weaknesses is subsumed in EotM, and can only barely bridge the gap between Diarmuid and Saber--and he's hardly a pushover. It's not going to help an Assassin.
I think you're missing my point like with the 'B- PC' stuff, so I grabbed some quotes to try and explain it. It'd be hard to catch if you watched anime only, which is a possibility. I was just using Knight Tactics as an example and you seem to be stuck on it.
Calmly studying the opponent's light footwork, Saber measured the timing of her strike. Lancer too was probably estimating the speed of her charge with the density of prana she put in her body. But she still has one more secret ready for that...
By a little, just by a little, Lancer's movement weakens.
The asphalt torn up into gravels created many obstacles for a good foothold. Lancer's movement stagnates a little when he puts strength into his legs.
Saber didn't miss it.
Saber's sixth sense can theoretically surpass thought for a natural talent for battle decision, but it didn't predict her blunder.
The idea is that instinct is only valid if Saber herself isn't the one messing up. It still doesn't full 'counter' instinct even if that's the case, but it can certainly help to pull off an ambush(Something normally impossible, though there are ways like for example Snake vs Saber)
Also, instinct is very weak to things you can't 'Understand', such as Snake-style. The idea for the dance Noble Phantasm was that it invites check failures in the actual dance moves, and that it's difficult for her opponent to 'understand' what she is doing. In other words, thematically it works a lot like the Snake fight combined with the Diarmuid fight- both things that actually work quite well against something like 'Instinct' or 'Eye of the Mind'.
Naturally of course someone with high ranked instinct can deal with both, as Saber has, but it still definitely gives you a first time ambush advantage on an enemy. It's an excellent way for an Assassin to score kills, and under the right conditions, even defeat Servants they normally couldn't with team support- Like True Assassin and the Shadow.
Keep in mind I'm only posting this since I don't think we've reached a very good understanding on what I've said so far, so I wanted to clear it up. I'll keep my mouth shut on further sheets and anymore discussion regarding instinct because you asked. I'll only respond to someone if they ask for advice over the OOC or via PMs. I don't like cluttering the OOC anyway.