he can guide himself, but hitting someone is tricky enough. Often you are lucky to even connect with an aware opponent, so you are best just aiming to hit them, your opponent probably has more control over what side you land than you do
I'm not the best Vega tho so it's possible I'm not using it that great. I'm trying not to use it too much outside of combos tho, its pretty easy to stuff.
The exception to all this is some set-ups in the corner, where you can easily decide which side you land on, so Vega can get a 50/50 with it. And dodge DP's too.