I'm sure at home the teams from the Hex can give and have given good to very good European sides tough games or took points off them in the past, even on neutral venues now and then it has happened (especially Mexico, US), but Arena surely isn't talking about the little islands. Even though many of those places have the benefit of French and British-born second or third generation players to aid the squads they are not any higher standing than a Gibraltar or San Marino, who are mostly semi-pro. They'd struggle with Andorra, Lichtsteinstein and Luxembourg, and lose by a few goals to the Faroes, Cyprus and Estonia. In fact Estonia went to the Caribbean to play some of these sides recently with a squad of local players and had good results.
The British island nation guys tend to be in non-league here, one or two in League 1 or 2. Even Haiti's most dangerous player is playing for my hometown club in League 2 at the moment

Actually he scored a couple against Japan last night.
Arena is talking about going to a jungle or playing on garbage pitches. You'd think the US haven't experienced that before the way he talks about it. They've only been playing games in those places for 85 years. A good coach changes tact and adapts to the conditions, you don't just do the same thing you always do when you are playing with a handicap.