I think your referring to Galactic War, not Guild War? I don't know what guild war is?
If you are referring to galactic war, a lot of the "trick" or solution to GW is focusing attacks on toons that are gonna wreck your day the longer they stay heathy/ living. My guess is, If your other guild mates are beating / finishing GW with squads lesser than yours than you must be attacking in the wrong order or precedence?
There are a lot of videos out there to help guide you on who / what to attack / take out first. That is a very important part to being able to finish a GW. The other thing I would recommend is; do not start out with your A-Team first.... Save them for later when you run into those "god" squads.
Again, there is a lot of good videos out there on GW... I would search here on the forums and you tube, hopefully it will help you.