LOCATION: Flat grassy field two miles wide, surrounded by a metal dome, no escape.
SCENARIO1: Sakura vs each titan, one after the other, one on one. The others can watch while waiting their turn
SCENARIO2: Sakura vs all three titans at a go
SCENARIO3: Neck weakness removed for titans
+Titans start in titan form, have knowledge of Shinobi and sakura personally, all current versions.
+Sakura has no knowledge. Base Sakura (shippuden) and then with seal activated for both scenarios (no summon).
NB: Not sure how fair this fight is to the titans beyond base sakura, am an anime only naruto fan so no concrete knowledge about her upgrades yet, beyond a few basic guesses.