I can definitely agree with Necro being more of a counter-zoning variant than an actual zoning variant... To an extent.
But I will say this, I am starting to use Summoned Fiend to snag teleport characters or people who like to wake up. It's good at a little before mid screen, Shinnok doing it any closer than that would likely get punished really hard, but I mean... It still has it's risks especially against those teleport characters if they delay wakeup and you mess up the timing. Something that is pretty common. If you can adjust to the delay wakeups well, Necro can very well be your kinda character.
The problem with Necro ultimately, is that you can backdash all but EX Flick and the unblockable (the unblockable actually still can but it's pretty difficult from what I gathered). You were able to do this before, and even though these moves are better now with tracking, they are still very susceptible. I would honestly say that even though Necro can do the 50/50s just like Bone Shaper and Imp, there's way, way more of a risk and he's read heavy.
But as I told
@GGA Max, something I know he would agree with, all variations are worth learning.
Mainly because Imp is really great for... Well we all know why at this point, he gets that damage and setups against characters he otherwise wouldn't get in all of his variations.
Bone Shaper due to the range and sheer damage that I think even Imp's Mimicry damage buff gets a bit jealous at, at times.
Necro if you wanna force your opponent in for sheer pressure and agitation. What really hurts Necro compared to the other two, and no I'm not asking for buffs, he's viable. Wound Cowboy just showed us this, but what hurts that variation is that he actually doesn't do too well against true zoners, but rather characters like Liu Kang in Dragon's Fire with low fireball, air fireball, standing fireball etc... Because Flick does more damage and it's a mid with no meter unlike Bone Shaper's Dark Beam. This is fine, because now we have three variations at least worth learning, that ultimately just give you different ways to incorporate him and his 50/50 mixups if not more with MB sparks on block.
@RM Jonnitti showed me that maybe you shouldn't even wait for them to be pushed back all the way, do it right away on the first one to allow you a B3, a grab, a F4... All variations can do this!
My view? Don't just be a Bone Shaper, an Impostor... Learn them all. Learn them all because you never know what you need against a character or a player if we're talking setplay and you know what they can do. Maybe they struggle against flick more than say, ATP or Dark Beam +8 on hit restands.
Just my two cents!