Well, they spent at least some of their time complaining, chasing after Moabite women, and waiting for the older guys to die. Given that Phineas’ action caused him to stand head and shoulder above everyone else, in the very least it seems that whatever was taught, it hadn’t sunk in very deeply in most cases, so even though the teaching on some level had been given to everyone, everyone doesn’t seem to have been that intent on preserving it. In short, they behaved like Catholics.
Moreover, the argument being advanced was that G-D had revealed the Torah at the nation as a whole in a way that is quite distinct from the way that Christian revelation is claimed to have been promulgated. After Exodus 20:18 if all that is advanced is your scenario—one individual in more direct supernatural communion teaching others, I think the distinction is largely lost, and if anything, ends up breaking the other way. Christianity holds that the seeds of revelation were entrusted not to just one (Moses) but to the twelve (working from Shem Tov’s text of Matthew the parallels seem quite clear—while in Christian tradition Christ has often been portrayed as a new Moses, it seems that actually the apostles are portrayed as the new Mosi (pardon the neo-logism). Over the next while, their understanding of what they have seen, heard, and handled deepens.
You understand the arguments. It is not a mistake that intellectual converts to Christianity mostly become Catholics.
The Catholic/Orthodox Tradition does indeed mimic the way Jewish mesorah is transmitted. Protestantism and its offshoots do not. Mimicry is not the real thing.
The Christian path does indeed lead to the Divinity of Jesus, the Trinity, the sinlessness of Mary, the authority of the Pope and the Church, and holidays like Christmas and Easter.