Indeed you would think so, but then you get into trickier issues. You think at first "We'll just put our ship further away, and rely on range" so you move your ship back. If you're in a fair fight with the enemy, then it's fine, but if you want an edge in battle you'd need to put most of your guns on one side, so that you can bring your full firepower to bear. After all, your enemy can only be facing you from one direction. So you have the advantage by putting your weapons to one side. Then again if the enemy can flank you with multiple ships, then they can hit your exposed backside, or if the enemy is faster than you they can push in through your fire and slip behind you. Or just push in and eject, hopping onto your ship and going close combat.
In a capital ship fight it'll be simple, two ships at long range slugging it out. Beyond that, it comes down to agility more than anything else. Anti-Frigate Cannons are the best, but because of their very slow bullet speed anything smaller than a frigate will evade them. So you'd want to mount smaller guns that can hit people at range. But then if the enemy has a very small ship with frigate-level armor on one side, they've got speed and armor. At this point you'd want speed, so you can circle them and hit their unprotected backside.
This is going to get into some complex fights, especially once it's 3 ships fighting, then it gets crazy. I don't think anyone fully understands how it will play out until multiplayer becomes an option. Only then will the arms race show itself.