Special Promos with Coupons

Hi there. I am using Hikashop Essential and I am trying to do a couple of special promos for my client using coupon codes. She wants to have these promos:

1. For 2 orders of the same product you get the second one 50% of
2. For 3 orders of the same product you get the third one free

Now I cant us the product prices because each product has variants that adjusts the price, so I must use coupons and apply percentages to reflect the promos.

Now if I select 2 quantities of the same product ALONE in my cart it works fine. If I select 1 quantity of 1 product and 1 quantity of a different product the coupon gets applied too. But it should only be applied when the quantity for one product is either 2 or 3 and the appropriate quantity applied.

So in the case of the coupon which applies a 33.33% discount to an order of a product with a minimum quantity of three, if I select three different product with a quantity of one each, it will apply the coupon since the overall quantity of the entire order is three. Is there a way to accomplish what I need done or does Hikashop not work that way..

So an update. Client has decided to have the promo to work on the overall quantity of the order. So the problem I identified is no longer an issue. However I have another problem.

Sometimes, the coupon that should work on "Buy one get the other at 50% of" is not being applied and instead the coupon that works on "Buy 2 and get the third one free" is used instead. So If I select two products with quantities of one each, the wrong coupon is being applied. I understand how this could happen, since the latter coupon has a Minimum number of products as 3, so then an order of 2 also falls into it. So is there any way to ensure that the first coupon is always applied ahead of this one?

So what would you advise that I do based on the problem with the second post. Are you saying that I would have to use the product price units.

I can't use the product price unites because there are also variants that when selected would change the price of the item. And also, I did try putting price unites and setting the minimum quantity but it did not even make a difference when selecting more than 1 quantity.

A little help please.