Agree.. The smaller the country and less the talent pool, Countries need to concentrate on chosen fields to gain success, Some times those can be sports they're traditionally strong with a long history or sports that they are have natural ability to be good at, As you mentioned the Caribbeans at Sprints, East Africans at long distance and Eastern Europeans at Aquatics, Even on a regional scale Lankans are good at Sprints and Swimming
For much larger countries of the world like China, India, The US and Russia can end up getting more medals all around on sheer numbers of participants and the investments they do on Sports, Even though some Indian posters here have already dismissed the notion, Numbers do matter significantly
Back to my argument about Pakistani's tend to be more natural athletes.. Well the opposition to that notion by Indians are expected, Well the best testament to my point is take the two sports that the both countries are competitive in at global scale Cricket and field Hockey, It's undeniable that Pakistani's churn out freakishly talented players throughout the years under trying circumstances with less funding, less infrastructure and less chances of succeeding than Indians overall.. Results speak for themselves, imo if those sportspeople are given equal opportunities we could see their true potential
Not taking anything away from Indian success in recent times at world stage, They have proven with the right investments what can we archived in a rather short period of time at that, The yearning to be recognized as a world power is also one motivation for Indian establishment for their success at sporting events