Long Range weapons

[korinthmalar]

Hi everybody!
I'm having a problem with something in Starfinder starship combat and I thought I'd ask here to see if anyone had a different understanding of it.
RULES: Long Range weapons (including the cheap-ass Coil Gun that can go on any ship) have a range increment of 20 hexes. So you can shoot up to 20 hexes without penalty, 40 hexes at -2 to hit, 60 hexes at -4 to hit, etc.
So if we're on a ship with a Long Range weapon and we're approaching our target, I'd probably want to start shooting as early as possible, especially if I think the target might have shorter-range weapons. Well, a -8 isn't so bad that it's not worth trying, so I should probably start shooting when we're 100 hexes away.
HOW BIG IS THE HEX MAP SUPPOSED TO BE?
I see Paizo sells a 27"x39" starship combat hex map with 1" hexes. If I'm right, then a ship at the center of the hex map with a turret-mounted coil gun could hit anything on the map without even taking a range penalty, begging the question of why no one did anything before the ships were on that scale of combat map.
Am I missing something here? Getting the rules wrong? Or is this (kinda basic) situation something that doesn't quite work properly?

[Jimbles the Mediocre]

I don't have a huge amount of experience with starship combat yet, but one thing to note is that you probably won't start combat 100 hexes away from an opponent.

Core Rulebook > Starships > Starship Combat (pg. 317) wrote:

In general, the GM decides when starship combat begins, where the combatants are, and which way their starships are facing. This might mean that both sides are facing each other from opposite sides of the grid. However, their relative positions and facing can also be established randomly. Roll 3d6+5 to determine how many hexes separate the opposing sides.

On top of that, you can't passively detect a ship at a range of 100 hexes:

Core Rulebook > Starships > Building Starships (pg. 300) wrote:

In starship combat, short-range sensors have a range of 5 hexes, medium range sensors have a range of 10 hexes, and long-range sensors have a range of 20 hexes ... Passive sensors detect visible or unhidden objects in a 360-degree field around the ship at a range of up to twice the sensors’ range category while in space or in the Drift (no skill check required), though local conditions may affect their range.

[Lane_S]

While rare I have started combat several range bands out in fantasy. Most common adjustments are tracking range off map or use a per square/ hex multiplier. If you have a way of detecting the other ship, or using active scan, you could start with each hex count as ten.

Long range weapons are also good at taking out an opponent that tries to flee.

[Cathulhu]

Coil guns seem to be very efficient. My group favors them heavily.