Given Camelot is screaming at her, Lilac just Lariat a pile of Pageless into the ground that Suzuya firebombed, and Roma looks bizarre in a bridal carry in front of her, I’d say she’s suitably distracted from a triple sneak attack to the back.
I'd say that she's so much of a battle-maniac, her instincts are hyper-tuned to combat stuff while drowning out everything else. She might even move without consciously registering said moves first, ultra instinct style.
Also this is the Monkey King she emulates, a kinesthetically-genius acrobat who's strong, durable, and agile in equal measure. My money's on Tesni when it comes to direct mano-a-mano physical combat, even when outnumbered, especially against familiars.
In the worst case scenario, she simply face-tanks the hits and then return the favor (at least) tenfold.
Well, I guess that's the performance of a Grimoire that's 90% focused on direct combat abilities, and the few that aren't direct combat abilities can be used to increase combat performance even further.