It makes no realistic sense for Chiyo to be able to master 10 and coordinate them at once but yet she does it. It's only hypothetical but imagine that 20 puppets all move at once with one movement for the sake of simplification. Clumsier than Sasori's swarm but just as wide-scale an attack.
This isn't about realism. If it were we could just take the whole manga, throw it in the trash can and go read something more down to earth. Rather, the point was that it makes no sense, physically (according to the Narutoverse standards) to control that many puppets. Chiyo was able to control 10 of them because she atleast had them attached to a finger which she could move in different ways. The problem with a 100 puppets is that there is simply no more fingers you can hook them on.
(You may argue that he could hook them on to his toes but that would be just lol-worthy.)
As for the hypothetical scenario, moving 20 puppets in one line would be a terrible move, since the point of numbers is to surround your opponet and/or distribute attacks from various angles so as to put the target in a corner. If they're just going to all act the same, Kakashi would easily see through it.
Interesting point, could you elaborate on the surprise attacks for me? Outside of the poisoned blades and projectiles, very few of their attacks are merely gimmicks to me.
Almost all of the puppet's big moments we saw were in forms of hidden weapons, functionalities which the victim didn't know of and this put them in a tight position. First puppet performance, Shino vs Kankuro - all the hits at Shino came from hidden, unpredictable weapons. Skip to Shippuden, Sasori won because he knew all the secrets the puppets held (including their weakspots which Kakashi may well be able to see with his Sharingan) and destroyed them with ease while deploying a secret weapon himself (the poison of which Kankuro was unaware). Moving on to the big Sasori fight, it was all a matter of: "oh look, he upgraded the puppet be careful", "he has Iron Sand poisoned as well??!", "100 puppets u wot m8?" - Sasori had a huge advantage there because the two didn't know what to expect (even Chiyo was suprised by the stuff Sasori threw at them).
Even if there were some significant attacks which weren't secret, their strongest abilities do require the element of suprise. Also don't say aside from poisoned blades like it's a small thing considering how almost all puppets' arsenal boils down to hidden weapons and projectiles. Do note that I'm counting unpredictable behavior (such as Chiyo's puppets combining their limbs) as gimmicks here.
Yeah, his performance against the Edo Jin Paths is great and why I thought him a good candidate.
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I like the idea of Chiyo using her puppet anatomy, shield and her secret ace taijutsu mastery.
I forgot about puppet anatomy. Still don't think it would mean much considering how skilled Kakashi is in hand to hand combat.
