The biggest thing when I build lists I ether devote it to being a Close combat army and do everything I can to make it effective at that. Or if I want to do a 'shooty' army I devote everything to that. My reason is simply because I would rather do one thing well and execute it properly rather then do half cc and have range at half effectiveness. some will disagree which is fine but thats my theory on it.
Best of luck!
Cheers,
Chaosftw