It is noted that even restricted by ME to straightforward, no-tactics hulk smashes, he still has the greatest abilities out of all the Servants in hand to hand combat; plus if one wants to get pedantic, it is noted that several, not all skills and techniques are sealed by his madness. Also, "ingrained" has the implication of "instinctual", and such things, like his Eye of the Mind, aren't affected by ME.
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Although saying that Lancelot getting EAM might've influenced the anime portrayal can't be discounted.