Fog of war.
Like in extreme mode only, how u cant see the enemies till u go into battle, 'cept u STILL CANT SEE THEM IN IT
not neccessarily a FOG so much as an area u cant see that contains their entire fleet, like half the map maybe, and u can only see into it by moving ur ships into range, like your weapon with the biggest range sets the “view area” and u need to move to discover more of the fog. It’d be cool, seeing like their fighters comeing out of this dark, black space, then their frigates, then like their entire fleet just looming up out of nowhere and opening up fire on ur ships.
It wouldnt actually change the range of the weapons, cos ur longest range weapon is ur view zone, so u can still fire when u could fire, and maybe to make it more eery they put in like gaps in the fog, to give u a glimpse of what is coming, whether to get the $%^& outta there or stay.
A bit like JAWS i guess, like it plays dun dun dun dun dun dun music when u see the enemy in the gaps