It's a different design philosophy. Zorro is designed not after MT4, but more after TradeStation or similar tools. All high-end platforms support pending trades directly, and thus normally have no need for tick based price comparison with all those problems of incomplete candles and so on.

Anyway, I think it is good to know the different count of candles in MT4 and Zorro, as other users will run in the same issue.

Early Zorro versions had indeed a tick based run function, and we can certainly reactivate it when it's needed for a certain strategy and there is no other solution.