Talofa...Samoans tend to be larger boned, holding more muscle mass, and stronger that the average ethnic groups (including my white bros). In other words, a much larger percent of the individual Polynesians, following the chain of islands from New Zealand to Hawaii , fall into this genetic pool. (Oh there are weaker runts of the litters sometimes, maybe 5'10 and 180 & only bench 300 or so, but they are usually drowned at birth) My two younger cousins would be classed as average for their race. Both were using 400+ for reps in regular workouts when they were 18 years old. Now play at two major football factory's, one bowl bound.
American Samoa (can't speak for Western Samoa) has a population of around 55,000. The Mormon Church brought quite a few over to attend mostly their schools years ago The natural progression was to play sports, football being number one. BYU, Utah, Utah St, etc being first choice but a lot of California & Washington state colleges also. From a very small population base, the NFL has quite a few Samoans on their active list. Two of my relations are retired (pension is crap) and one is still active. Funny thing is is that American style football is not that big a deal over on the island(s). It's soccer & rugby (Aussie and New Zealand leagues have Samoan players).Their natural hip and leg drive give a advantage to power sports like rugby and football.
Why not that many Samoans in BB'ing or lifting? Because they don't seem to care that much when most of them are already bigger and stronger than most. They will workout but not always with serious intent. Samoans, for the most part, prefer combat style sports, like football, here in America. Not always the happy, friendly natives when sports are involved, very competitive & aggressive. English explorers compared them to the Irish when it came to a fighting and the warrior spirit. (Sonny S. grandfather was German. Germany once owned most of the groups of the Samoan islands) Good Luck.