While that could definitely be a natural initial conclusion there’s definitely alternate directions one could go without encroaching too much (or at all) on others classes’ playstyles or themes.
Some example rough concepts for some necromancer specs:
Animator: This would be the “pet” focused one, but in instead of summoning a hordes of minions like Unholy DK or Demonology Warlock, they would focus on creating a single, powerful minion to fight for them.
They’d begin with either a simple skeleton or even no pet at all. As the attack they’d build up a secondary resource (flesh pieces or something like that) which they could then use to create/further evolve their pet. There could be 3 or 4 different pet “evolution trees” that you would have to choose between based on the fight and current situation.
For example one could go Skeleton → abomination → Flesh Giant for melee single target
Skeleton → bone golem → bone wraith for aoe (BOOONNNNESTOOORRRRMMMM!)
Spiderling → Crypt Fiend → Cyrptlord could provide CC options
Each “evolution” would deteriorate overtime so you’d have to rebuild it and/or try and maintain it (with diminishing returns.
Cultist: Thematically this spec would focus on casting off the chains of life and ascending to undeath (or a greater level of undeath for any forsaken players). The goal is to become a Lich (or demilich if people need a reason that it’s only temporary). While in your Lich form is when you do your most damage so obviously maximum uptime is the goal.
You’d have two gauges. One would be the Phylactery the other would be your body. They share the same resource which is your soul energy. The phylactery’s soul gauge is constantly draining and your body’s soul gauge is constantly filling. While not in lich form your abilities spend your body’s soul energy and the soul you spend fills your phylactery. Once your phylactery is full enough you can enter your lich form.
I’ve had a few different thoughts for how lich form would work. I think it’d be cool if while in lich form your health bar became the “timer” and that when you hit zero, instead of dying, your soul would release from your phylactery and you’d come back to life. Your spells would do damage to yourself and you’d take increasing damage from all sources over time. Sadly I don’t think this could work with out a lot of extra restrictions as it’d be really powerful in pve and pvp especially if you had a really good healer. You could also cheese a lot of mechanics.
So for now i’m still thinking of a way for it to be cool and unique.
As I said these are both just rough ideas i’ve thought up in some of my spare time. Obviously a lot of stuff would have to be fleshed out for these to be made into playable specs but the point is that there are definitely other directions you could take that still keep to the traditional necromancer theme without stepping on the toes of other specs, thematically or gameplay wise.
Just because some classes/specs fill the role necromancers traditionally take in other games doesn’t mean there’s no way to introduce them successfully.
Also to be fair, there’s already a lot of classes or specs that share not only similar themes but similar play styles with some of the biggest differences being primarily visual.