That is not what you said in the cavaet, you said it needs to be the official language of the said country and in most of these countries it is the sole official language.
Yes, i also said it needs to be a primary language which in all African countries, indo-european languages are secondary languages beside their own native or local language.
Germany has a population of over 80 million and German is not only an official language there, but also in Austria, Switzerland, Luxembourg and Liechtenstein