Fireball - Impact vs Scorch

Maybe I'm just missing something here, but I noticed (what I see as) a huge flaw.
Under the fireball skill, there's two upgrades - Impact and Fireball.
When Impact is unlocked, a charged fireball will knock down enemies and briefly stun foes.
And with Scorch, a charged fireball will reduce targets chance to hit by 25% for 5 seconds.

So is there any benefit to getting both Impact and Scorch? I figure if you've unlocked them both and they happen simultaneously, then by the time that they get back up, the benefits of Scorch have already worn off. Seems like a waste to get both, in my opinion, but I'm happily open to any corrections.

I think the 25% hit debuff lasts much longer than the knockdown time. :)

maybe Scorch works on boss that can't be knockdown,so the 25% get on use

I agree and wish makers of the game weighed in on this. The 25% debuff sound crappy when say 3 of the 5 seconds of its duration is actually wasted on the monsters sitting on the ground :/

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