Of outstanding imporatnace means= something important, that's all.
The whole question merely means, The outcome of whoever in charge is very imporant.
I'll give you a couple of paralell sentences to help you see: I didn't know what it was but whatever I saw was of lightening speed.
John is a person of high integrity = John is a very honest and trust-worthy perosn.
When you use "of " in this context, a noun or noun clause must follow.
His action was of irreversible consequencies, meaning what he did can not be repaired and redeemed.
Hope my explanation helps!