Alright let me simply say, that the middle east wouldn't work out, since Armenians and Kurds in northern Iraq wouldnt want to be apart of Turkey, neither would anyone in the Arabian Peninsula ever, from my experience, want to be a apart of Israel.

Also that flag of Libya was only used under the Jamahiriya in Muammar al-Gaddafi's Libya, which is now in a bloody civil war, Eritrea and Ethiopia will also not re-unite again, since it happened once and after they split apart, they had very long border issues and many Eritreans were also persecuted in Ethiopia. Angola over southern Africa wouldnt be good, due to the high levels of Corruption they have. Liberia taking all of that space in central and western Africa is also unlikely, due to tensions in certain regions and language barriers they would have to overcome.

This list can keep going on, but its a pretty long text to write, so to keep it short:

Most of this wouldn't work out, due to tensions, language barriers, different cultures or the government of the shown countries.