We're referring to a regular Uchiha's capabilities in general, not fodder genin.an uchiha? Who are you talking about specifically? I don't know a single genin uchiha capable of genjutsu in that situation.
Except Chiyo admitted that multiple ninja was needed to handle the 3T Sharingan despite them having knowledge on Itachi's Genjutsu. Knowledge isn't helping Kidoumaru evade it.not to mention Kidomaru has knowledge on dojutsu so staring at an uchiha would be stupid.