Is there any limit to your stupidity? Where do you think the holy order troops come from? It is a handy abstraction for arrival of fresh volunteers from Europe. Secondly if you had bothered to learn to read, in the real first crusade the Duke of Lower Lorriane takes it all and keeps it for himself. Which is exactly what CK2 allows to happen.
If this was CK, you'd have 0 in diplomacy.
Duke of Lower Lorraine beating the Moslems alone? And you have yet to show mechanics that the crusades will be organized.
Ok, he's going to buy hordes of mercs and order troops, but that doesn't cover the fact that he had several allies with him, including hordes of volunteers from all of Western Europe, ranging from peasant to nobles. And allies are only through family as far as you have yet revealed. And how will Peter the Hermit's peasant crusade be handled?
Overall, with the information you have given yet, the chance of Godfrey becoming king of Jerusalem is zero.
I sincerely hope you have either made the AI for crusades very good or made some mechanisms we have yet to hear. For a game named Crusader Kings, the crusades already seem to be very poorly handled.