Distribution of creatives to adsets
At the stage of filling the bundle, in the "Creatives" section, you can select the filling scheme.
There are two schemes:
All-All - with this parameter, all uploaded creatives will be loaded in each adset, that is, for example, if you upload 3 creatives, all 3 creatives will be in 1 adset.
1-1 - with this parameter, 1 creative will be loaded into 1 adset, for example, if you upload 3 creatives and select 3 adsets, then each adset will have its own creative.
If the 1-1 scheme is selected, 4 creatives are loaded, and 3 adsets, then 1 extra creative will not be used in any adset, if there are 4 adsets and 3 creatives, then the random creo will be loaded again into the fourth adset.