Yeah hyperlanes are a huge RNG and can both benefit you greatly or absolutely destroy you... In the last few games, I had very nice hyperlanes. At one point, there was only one huge chokepoint that connected my homeworld sector to rest of the galaxy, until mid-late game (if you are lucky) AI doesn't usually have jump drives, so that chokepoint was really good at holding people back (had about 16k citadel there) and basically everything behind the chokepoint was mine. About 20 sectors or something.
I haven't played Grand Admiral difficulty yet though, and probably wouldn't. I am a military freak and usually start spamming fleets very early on.
Militarist Gestalt!