Enforce sales agreement price in sales order

Hi,1. We have a generic modifier (10% discount) for an item category TR.0.0.

2. We have sales agreement for a customer and item combination with 12% discount.

When a sales order is created manually with agreement number (not via create releases from sales agreement), both the discounts are applied as the item is qualified. We want sales agreement discount only to get applied in this case as this is the final price. Any way to stop other modifiers from being applied with out incompatibility setup?

Regards

User613456