I am thinking that the Zero and the Empulse, or Plus for that matter, are not going to be directly comparable with each other. While the closest match might be the ZF6 Zero S and the Plus, they still are not really butting heads. I think the market will be able to absorb both brands and the customer will be able to select the model, style and performance that fits their needs, as they travel up the price range.
It may also depend upon the number and location of the two brands' dealer outlets. As I see it, there are a very limited number of customers within a geographical area who are in the market for an expensive electric motorcycle, with limited range and performance, at a premium price. The more dealers a brand has, the more likely they are to satisfy this limited demand within each market area.
Whatever happens it is going to be fun for anyone interested in the marketing of electric motorcycles, such as me.