I dont think thats how it works.CE likely works similar to say Chakra in naruto.Kid naruto had more chakra than kakashi but wasnt as physically strong.I think CE manipulation matters too.Yuta has absolutely no feats to say he can compare to Gojos raw strength.Gojo is someone who can exorcise people like Jogo and Hanami with JUST physicals.Yuta also compares his physical strength to Yuji("Youre the complete opposite of me.")
Also, if it works that way for strength then it likely also works that way for speed.Gojo is the fastest sorcerer, meaning he is faster than Yuta and thus likely stronger too
Firstly :He might be talking about it in this way : Gojo wouldnt be able to protect Jujutsu High, he may not be meaning that he would be able to beat Gojo.Even with Rika he has no counter to Domain.Im also pretty sure she cant bypass infinity.
Secondly : Being special grade doesnt mean you are equal to another special grade sorcerer in stats.Geto is also special grade, but he doesnt exactly scale to Gojo.He also never says Yuta will surpass him, just that they will grow to be as strong as him(as adults).This is him talking about their adult versions.He also says this about Yuji(but not Megumi).
Third : Where was it stated he thought that Yuta would handle Kenjaku?AFAIK Gojo only says he would take care of the first years(especially Yuji).Kenjaku is likely stronger than Jogo and Mahito, and both of them have DE.
Geto and Gojo were "comparable", Gojo was stronger.Toji had planning,a direct counter to Gojos CT,a kind of counter to Gojos Six Eyes, and had Gojo let guard down during his fight.Gojo was also really exhausted.Despite this he performed a lot better than Geto did(Who got negged) despite being at a massive disadvantage