I propose for a change in the bonus for two continents: South America and Africa
South America: 3
Africa: 4
(No changes to N.Am., Europe, or Asia)
Reasoning:
S.Am: Oceana provides a 2 bonus, but has only one border. S.Am. has two borders and is much more difficult to defend than Oceana, plus is in a more fought after areas, whereas Oceana is at the back end of Asia, which is rarely fought over.
Africa: Africa is in the center of the map and between S.Am and Oceana - a likely thoroughfare and battleground - causing Africa to be a difficult continent to defend.