Believe me .The MNCs are the first to go to most countries not advised to go by their nations.Oil exploration,mineral giants followed by telecommunication,shipping and aviation are the first in the que.
Singapore government or quasi government companies are no exception.They trade with their militias while advising us not to.
Thakral was in Nigeria not because they know better.They simply tapped on their Indian diaspora connections. ethnic Indians control African businesses.They are Chinese too.I know of a Chinese family from HK whose relatives stays in Nigeria for good.
There is another foreign diaspora that have been in Nigeria and parts of West Africa for a long time which are the Lebanese - mostly from South Lebanon. I don't know many typical singkies who are aware of how ethnic distinctions play a part in these countries but the Lebanese in Africa along with the Indians have generally entrenched themselves into the various businesses for a long time. I was introduced to one of these Lebs in London years ago and he not only considered himself a Nigerian, but ran an oil trading company and was married to Nigerian girl from the north - he knew no other culture.
Nigeria as a society is also segmented between Yoruba, Hausa, Ibo etc tribal divisions and coupled with religious differences has made it an explosive cocktail for chaos and civil exploitation. There is a very good reason that Nigerians are generally feared by other West African countries because of the sheer size of population and there very aggressive outlook to life. There are always opportunities to survive and prosper but it also depends on how adaptable one is to such environment and the extremities.
I have dealt with people from all walks of life including Nigerians - like in any country, there are good ones and a lot of poor and very aggressive ones. If your cousin is streetsmart and ballsy enough, then that is probably 50% of the battle sorted - but it also depends inn how versed he is in engaging with people of different ethnicities and understanding the nuances of their cultural and societal outlook. There are parts of London that most middle-class white or brown people would not go to because of the high concentration of African immigrants and the usual tabloid fodder about muggings/stabbings. From my experience it comes down to how you also carry yourself - people will try it on if they think they can get away with it. The trick is whether one has the type of personality where these types of characters are weary of you because they think you are dodgier than them (just because of the way you speak and carry yourself and things you speak about).
I had lunch yesterday with the Assistant GM and GM of Audi/Volkwagen from Iraq - the GM had spent 6.5 years in Sudan, then posted to Kenya and now in the Kurdish part of Iraq - the Asst GM was of Iraqi origin but told me he never thought he would in his wildest dreams he would ever work in Iraq after the fall of Saddam but it was an opportunity and he was willing to try it - he is married and has a young child but he moved to family there anyway - he also said companies as part of the strategy in Iraq set up in Arbil with a view to eventually moving to Baghdad in the future.
Both were very cheerful and optimistic individuals and were of the view that everyday living was just that - newspaper articles may paint the picture of a country in perpetual chaos but as is quite usual, inhabitants just get on with their lives. The only challenge would be around the time of Ashura when religious sentiments run high and the processions become targets - both do not live in gated compounds (the GM is an old English guy from Leeds) and said all the apprehension they had was overcome once they started living there.
The opportunities are always there in such god-forsaken landscapes and it is a question of degree. Just hope your cousin does his research and finds out what packages for equivalent Western expats for that role would be - there is no reason for him to receive any less just because he is singkie (other than for the lack of experience required which ought to be reflected in the basic pay and not the other components of the package being offered). He should also speak to some recruiters to get an idea of what to expect at a minimum and then negotiate from there. If they want him more than he needs them he should not settle for less.