As smart as Shikamaru is, and he can well strategize against most...he can never beat quality ninja, ninja with actual power, more power than him. Which is why he got beat by Temari during the chunin exams. Yes he out-strategized her and had her caught in his shadow clone, because of the huge gap in their power, Shika could not follow-up and do anything after that and he was forced to give up cause he ran out of chakra
Then there's Tayuya who also beat his but. Yes he figured out her technique and strategized a way to beat her, given her greater power thans to the Curse Seal, Shikamaru didn't stand a chance of beating her; hence why Temari had to come in and save his behind.
All the great planning in the world doesn't mean a think if you don't have what you need to follow up. Most nerds can outsmart the biggest jocks in their school, but there's a reason why they get pounded by the dumber jocks. The jocks have more strength while the smarter nerds don't have the strength to make their strategy work