Sadly it's not objectively false, it's merely vague. There's no equivocation whereby it actually specifies that the unit of measure is the individual animal, rather than, say, kg. It's just playing on your assumptions (I did assume biomass fwiw, but who cares).

But anyway, the point made by sheer fucking biomass imbalance is surely the thing to focus on here? Now that we know what it means, and are in agreement that the wording should be clearer, the statistic is still egregious, isn't it? Humans have taken far too much of the world for themselves IMO. Vastly diminishing returns for us, devestatingly larger impact on the environment, the more we push it.