In my opinion i think ritsuka is definitely way better than kadoc and paisen combined, but when it comes to actual fights besides pure on servant command i think ritsuka is below kadoc because of what happened on LB1 where kadoc used his knowledge of the lostbelt and ritsuka's kind nature against them by revealing what would happen if the tree got cut down, that is a great move and it also almost ended ritsuka if only paxti the goat didn't save the day
Kadoc's advantage was confined pretty much just to LB1, though, due to his familiarity with it and due to his connection both personal and otherwise with Anastasia. Outside of that, Ritsuka has the advantage in terms of combat experience (a lot of Kadoc's initial inferiority complex is being ass-mad that a literal no-name mage like us managed to save the world from Goetia, where he and the rest of A-Team, almost all of them from big-name Mage families, failed) and Ritsuka's sheer ability to connect with All Of The Servants, whereas Kadoc is still hung up over Anastasia; the one summoned to Chaldea isn't
his Anastasia so he kind of politely avoids her.