add _trader= before each trader like this:
_trader=
[
"Exile_Trader_Aircraft",
"WhiteHead_17",
["HubBriefing_scratch", "HubBriefing_stretch", "HubBriefing_think", "HubBriefing_lookAround1"],
[10491.3,27367.8,0.1],
50
]
call ExileClient_object_trader_create;
_trader setVariable ["ExileTraderType", "Exile_Trader_Aircraft"];