I'm only referring to the fact that you are allowed to use Ad Unit IDs from multiple accounts in your app in general. Now having more than one AdView on the
same view is something else. I would not be able to talk about Ad placement policy related questions but it is advisable that you do not do this. You can refer to our
Best practices and
Banner implementation guidelines for more info. Alternatively, you can contact our
AdMob Product Help Center team for more about ad placement policies.