Testing Email Variations with Smartlead and Clay: Key Considerations

Question on smartlead and clay. I have 3 different variations of emails we want to test out. They each have different variables that needs to be filled from my clay table. But some of the leads will have variables missing for one of the copies. Will they automatically reject the email copy it doesn't have variable for and go with the one it does or will have to put the email copies in different smartlead campaigns.