Naturality of strong-epi-mono factorization

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We have the following diagram:

enter image description here

We want to prove the existence of such $h$ with $p$ and $q$ strong epimorphisms.

  1. Why can't we apply directly the definition of strong epimorphism to the epimorphism $p$, the monomorphism $j$ and the lift $(q\circ f , g\circ i)$ ? Wouldn't that immediately give an $h$ that makes everything commute?

Borceux instead does this:

enter image description here

  1. Do we ever use $q$ is (strong-)epi and $i$ is mono?