There is an undeniable advantage to fighting in your home state, province or country or even continent.
As MMA becomes truly global, are we going to have to start acknowledging the influence of fighting at home or away. In soccer it has been acknowledged for years the huge influence of home advantage or away disadvantage. Once a fighter is based primarily in one particular gym or country, or wherever they call home. The place they then fight can have so many affects.
Time difference
Country
Home Crowd advantage
Food
Familiarity
Facilities
These are just some examples. There may be more but they are huge factors. There are of course ways that a fighter can negate them. Like going to the location earlier. Having their camp or part of their camp at the destination. However, overwhelmingly there is an undeniable advantage to fighting at home.
Foe years this has been recognised in soccer. A win or a loss could be marked (subjectively in some cases) with a H or A for home and away. You would never get the same odds for a match between two teams at each respective location. Odds would be weighed toward home field advantage.
Japanese fighters fighting in Japan will win more fights. I think it will be really fucking hard for fighters to go to Brazil and pick up a win yet the same fight may be marginally easier if they were themselves at home.
Brazil is a cauldron and there is huge national pride at stake and performing at home for them is rare and therefore not taken for granted.