Yes, I think we have to view this as a "baby steps" process. But it is incorrect to say that a baptized person (even one baptized by a protestant) doesn't have faith, hope or charity. They may only have such graces for a short time - until they a) understand protestant heresy, b) fully embrace it.
But what's the alternative? They accept novus ordo catholicism? Is that better than protestantism? On some things it is, and some things it's not. Protestantism is so wide-ranging - from the wiccan-influenced "mega" churches down to the super strict southern baptists.
The way I see it is - the Holy Ghost never stops pulling people towards the Truth. Until someone is dead or until they harden their hearts, He will lead them to the Fullness of the Faith. It may take years, or decades. Practically speaking, the protestants are the only ones out there "preaching" so it makes sense that Muslims convert to this type of "christianity". Only God can bring good out of error. Trads are so few...unless a muslim stumbles onto a Diamond website, how would they convert to the TLM?