Are discounts being summed?

I want to use your plugin to give a discount for wholesale partners e.g. 20% for all products.
Besides I want to give special discounts for any other retail customers (non wholesale, not registered, not logged in) – e.g. temporary discount 10% for T-shirts. Realised by a standard Woocommerce sale function or by your plugin (is it possible?) or by another plugin.
I don’t want these discounts to being summed. I mean, if a wholesale partner orders T-shirts, gets only 20% discount (10% discount of T-shirts is not added).
Is it possible with your free or payed plugin?