word choice - Avoiding "existential it" while referring to a past event?

I know the use of "existential it" is frowned upon, but I'm not entirely sure how to rephrase the following sentence to remove it:

It is hard to tell what would have occurred if the battle had been lost.

Is something like this really all that bad? How can I rephrase this to remove that "it"?

Answer

That sentence is not using the "existential 'it'" that's frowned upon; it's just using an ordinary, unexceptionable feature of English grammar.

The "existential 'it'" that's frowned upon is the it that can be replaced by there; see e.g. http://www.odlt.org/ballast/existential_it.html, which gives the example of "It was nothing I could do" meaning "there was nothing I could do." But obviously your sentence cannot be changed to

*There is hard to tell what would have occurred if the battle had been lost.