No, what they were saying is you will NOT win against a station or ship that is 3 times yours in any direction.
So, since you are kind of new and can't be sure your ship will be the most extraordinarily efficient ship ever, do these:
1) Build your ship with at least same size as the enemy or bigger. Especially if the enemy is a station. Stations do not need thrust, jump devices and other stuff you need so they can and will be more efficient than you. (More punch for the same size/mass.)
2) On your ship, use previous good advice about weapon types, secondaries, tertiaries, right proportion between them.
3) My own advice that nobody ever follows: For a huge boost in efficiency and fun time in game, make your military ships have no interiors and make your gracious and beautiful interior ships not military. Just do not put weapons on a ship with more than 1-2% empty space inside and you will be happier, no matter how convoluted or simple, ornated or not is the ship's outer hull.
Or, if you want to stick to your size, choose to only fight enemies smaller than you. (It's like in high school, in a way.)
Also high school knowledge that applies perfectly in Star Made: consider skill (both in building and piloting ships) like martial arts. If your enemy is big/strong enough to split your skull with a single punch, you can not win and all the martial arts you learned mean nothing. RUN!
But between similar size/strength opponents, martial arts make all the difference. So if you can not win, either spend years learning either just go bigger.
Do you remember the Loki-Hulk confrontation? "Puny God!" Loki was an immortal God, but a small one, so...