According to Global Firepower, Nigeria is ahead of Ethiopia and is number 4 after South Africa, Algeria, and Egypt. Another thing that busts this list is, where is Eritrea in this list? It should have been right after Ethiopia.
http://www.globalfirepower.com/countrie ... africa.asp
Folks, something lost in all of these is, having big military while being poor is stupid. Compare Ghana with Ethiopia. Ghana is ranking number 15 in the link provided by the OP, but produces the largest number of scientists and engineers in Africa more than any other country except Nigeria, whereas Ethiopia is very poor and needs financial aid from US and EU for even their government's annual budget. Self-sufficiency should be a priority, and not a useless military might that can crumble after 1 or 2 sorties that US launches against them. Look at Japan and Germany - Smaller military but the leading economies in the world after the US and China.
In reality, large African militaries are designed to suppress their own people, so there is nothing to be proud of this list. It is a waste of money, useless way of thinking, and very primitive as well.
As for Somalia, a nation under occupation should not be in that list. The West has no intention of seeing Somalia standing its own feet with a capable military that can defend it. The current arms embargo is not intended to prevent small arms and ammunition from getting into Somalia, but to prevent Somali government and Somali regional governments from obtaining latest equipment so they can defend themselves. For instance, Kurdistan in North of Iraq is regarded as part of Iraq, but they have the best military equipment in Iraq. Why? Because the West wants them to withstand any attack from Shia or Sunni Arabs in Iraq. In Somalia, the goal is, no entity should exist that can deny nor challenge the Western multinational companies when the moment is right for these conglomerates to come in and loot what is below the sand and what is buried in Somalia's continental shelf.