The Catholic Church has formally defined and declared what is to be believed as a Catholic. Fundamentals of Catholic Dogma by Dr. Ludwig Ott is a good reference. Although there may be individuals who have divergent opinions on those beliefs, the Church has officially defined what is to be believed.
No doubt there are denominations within Protestantism who have done the same, but the set of defined dogma for a denomination does not apply to all of Protestantism, which results in some of the "strongest disagreements" as you said.
Do Catholics know what Protestants believe? It depends on which denomination they claim, and since there are many it is likely that a Catholic or even other Protestants don't know what they believe.
That is neither an infallible list, nor is it comprehensive in scope, and does not negate my list.
No doubt there are denominations within Protestantism who have done the same, but the set of defined dogma for a denomination does not apply to all of Protestantism, which results in some of the "strongest disagreements" as you said.
I am not defining or defending all of what is called Protestantism, but showing that the most basic belief of the Reformation, that of the status and esteem of Scripture, has resulted in a greater degree of unity than the overall fruit of Rome, as they are manifests.
And if you want to engage in comparing actual churches, then you should compare the unity of single Protestant denominations with unity manifest in Catholicism.
Do Catholics know what Protestants believe? It depends on which denomination they claim, and since there are many it is likely that a Catholic or even other Protestants don't know what they believe.
Again, this is true, though in my group answers are more uniform (and i am a former active and serving RC), yet in engaging Catholics here and in other forums, I often need to ascertain what group of Catholics they best fall into, with Rome considering them all to be members. I must do likewise with Prots in general. We are sadly not in Acts 2-5.