i live in europe and i never heard they dominate cocaine, nigerians have not enough money to run drug at highest level they are mostly mules for bigger groups and yes, in italy the nigerian gangs are little and weak, puppets of italian oc i don't know honestly if in other european countries they are more powerful, maybe in france they are something more but they don't control any european city and probably even any european single neighbourhood so they are nothing compared to ndrangheta in europe they are very strong only in africa
I agree with 99% of what you wrote expect for that. They are def. not the 'Ndrangheta, nor any other European OC group, but I bet that they indeed control some urban areas of certain EU cities. Not much yes, but a couple of neighborhoods? That I can believe.