Ok, it seems that if you wanna do a necromancer character, the way to go is with a wizard. I tried a bit with the sorcerer and going with the abyssal bloodline and with inquisitor/monster tactician, they are really good for summoners in general but they dont sinergize well with undead summons, you lose the necromancy school slot of the wizard and lose the buff for undead minions from Crueromancer, what is a big deal as the summoning feats dont work with undead minions.
So, my starting allocation for Cruoromancer/Eldritch Knight to be lich necromancer build:
13 S
18 D
12 C
18 I
10 W
8 C
Really dont like a pussy mage on the back that melts when enemies get nearby, so, some decent AC, good intelligence, need to improve a little to cast 9th level spells but not that hard to do, little bit of constitution to not be so terribly squishy and enough strength to get the Cleave perks what wont be that hard with the extra fighter feats from Eldritch Knight. Only doubt is that Eldritch Knight only start counting as a spellcaster level from level 2 forwards, that leaves me with only a single level to multiclass with something without losing access to 9th level spells.
Does Arcane Enforcer exploits work with spells on the wizard spellbook or with only its spells? The +2 DC for spells exploit in there looks very interesting.