Uncle Phosgene
First time out of the vault

I'll keep this simple.
Necropolis is canonically in Bakersfield in the lore. The directions given to you to get to Necropolis and describing it's relation to other locations fits that location rather than where it is (Set saying the military base is far north, which is true from Bakersfield, misleading otherwise) and the order of the Mutant Invasions(it being conquered second makes zero sense in it's current spot, perfect sense in Bakersfield). So move Necropolis and it's associated random encounters to the Bakersfield spot(which already has a small city tile).
And to fill the empty spot left by it? Put Scrapheap from the demo there. Powerscaling wise it helps fill a bit of a gap between badly armored guys with mostly rifles and the occasional uzi in The Hub, to the fully armored high power weapon super mutants. Scrapheap is mid level armor and weaker automatic weapons, with the bosses having miniguns. Helps fill that gap. Also it stops Junktown from having two companions, move Dogmeat's encounter here like in the Demo and keep Tycho in Junktown.
Necropolis is canonically in Bakersfield in the lore. The directions given to you to get to Necropolis and describing it's relation to other locations fits that location rather than where it is (Set saying the military base is far north, which is true from Bakersfield, misleading otherwise) and the order of the Mutant Invasions(it being conquered second makes zero sense in it's current spot, perfect sense in Bakersfield). So move Necropolis and it's associated random encounters to the Bakersfield spot(which already has a small city tile).
And to fill the empty spot left by it? Put Scrapheap from the demo there. Powerscaling wise it helps fill a bit of a gap between badly armored guys with mostly rifles and the occasional uzi in The Hub, to the fully armored high power weapon super mutants. Scrapheap is mid level armor and weaker automatic weapons, with the bosses having miniguns. Helps fill that gap. Also it stops Junktown from having two companions, move Dogmeat's encounter here like in the Demo and keep Tycho in Junktown.