It seems like you're asking how it is possible that "the result" can appear after "(with) tiredness and underperformance."
It's an example of what's called a small clause, "a frequently occurring construction that has the semantic subject-predicate characteristics of a clause, but that lacks the tense of a finite clause" (here). Small clauses are complex, but they can consist of two noun phrases, in for example, the sentence
- The witch made John a pig.
In this sentence, "John a pig" is a small clause. It is an example of two noun phrases ("John" and "a pig") appearing side by side in a subject predicate structure.
Another example involves the definite article 'the'. For example, consider
- They elected the man the president.
Here "the man the president" is a small clause. We have two noun phrases ("the man" and "the president") occurring side by side in a subject predicate structure.
But small clauses can also be made out of prepositional phrases and noun phrases. For example, in the sentence
- The witch turned John into a pig
the case can be made that "John into a pig" is a small clause. Here, the prepositional phrase "into a pig" appears after the noun phrase "John".
Although your example involves the preposition 'with', I am uncertain whether it's closer to the two noun phrase examples or the noun phrase and prepositional phrase example. In any event, "(with) tiredness and underperformance the result" can be viewed as roughly similar to "the man the president".
I hope these examples have shown you how two noun phrases (or a noun phrase and a prepositional phrase) can appear side by side in a subject predicate structure.