there are retrictions in some squads about switching sides............silly 
also to help your thoughts ARDY123, instead of looking for someone to just randomly fight. look for the ones that are a threat to your country and fight them. break them up befor the hord forms ???
yeah, good luck, I'm not talking about your garden variety horde, its an organized group that goes at it in the wee hours of the morning, when the arena is mostly dead. Its more akin to a mission but its usually perpetuated all by one squad.
aka, there will be some base that has no action all night, then all of a sudden, entering the dar will be 30+ planes all at the same time, and within 3-5 min, the fh is down.
As kappa pointed out, there are some maps where the bases are farther apart, and as such, by the time you get there from a neighboring base, the field is taken.
I usually enjoy going after the horde, but the recent change in their attacks to prevent any defense (going for the vh & fh first). My goal is to be able to fight them, I don't care if I loose, I just want the opportunity.