the resources are meant to be raided, IMO.
the best way to prevent this is to spend all of what you dun need.
The trophies system work in such a way that you take trophies from others and level up your rank. so it's never a good idea to lose trophies at any stage of the game.
although i understand why sometimes you'd place your TH outside of defense to earn the 12h hours of upgrade time, however i do not think deliberately doing that long term to keep your trophy count low is a good thing to do.
as you raise up your level and ranks, it'd become harder for you to beat other bases's defense, as your opponents are now stronger too.
well there's never a CORRECT way to play the game so that's just my take.
the point of this game, afterall, is to build the best defense, while mounting the strongest offense, and EARN TROPHIES to show how awesome you are. hahaha.
you dun have to agree with me btw.
those who havent got enough defense are always welcome to ask for reinforcements =)
P/S: upgrade your clan castle ahead of your other structures, the attackers will be in for a shock when they try to steal your resources/trophies

coz our clan is very supportive