Yes, please go on!
"Go on" and understand the history and relative states of mayhem in each of those cherry picked countries BEFORE, DURING and AFTER British administration.
In most cases, relative stability was maintained during British administration and Governance, only for countries to again collapse into despotic and corrupt cesspools almost immediately after claiming independence.
As for your personal favourite, Sierra Leone?
The British allowed independence of a relatively stable Sierra Leone in 1961 after many decades of administration and rule.
The independent country only made it 3 years on its own before corruption, power and greed re-took the country. The Governance unravelled back into violent single party rule.
Then:
1967-68. Three military led coups within just over one year, involving the removal and then reinstatement of Independent Constitution.
1968-1991 Continuous party state of rule by military force, with multiple violent coups
1991-2002 Civil war, including numerous coups
2002 War ended following the reinsertion of British troops and British negotiations for cease fire to restore peace
2002-15 British troops and administration remain to oversea the country to this day. Many Sierra Leone residents want even more British involvement!
