I'll answer your question by giving an example of something related.

Curze could see the future (or at least the various possible outcomes).

The Lion had no such foresight.

In a dual between the two, the Lion still wins because because he's just that much better as a fighter. Curze may have been able to see the Lion's attacks before they happened but didn't have the skill to defend himself against all of them.

Coming back to the weird 2 headed bird daemon, there is a big difference between seeing what will come and being able to do anything about it.

2 other examples:

Sanguinius saw visions of Horus killing him for a long time, he was able to experience every possible action and death of that fight, yet Horus was still able to kill him.

The 2nd example is even more relevant, I'm pretty sure I've seen an excerpt where Fateweaver attempts to convince the Lion to betray the Emperor. Upon meeting him, Fateweaver realises that there is nothing he can do or say to corrupt the Lion. Seeing the future is cool but sometimes it just confirms that sometimes you're not going to win.