Alright time to set the record straight before people start taking this NerdJosh thing out of proportion.
First of all I think Nerdjosh is a great player and is an innovator in his own way. He's not a "fraud" or a bad player at all. He is not afraid to experiment with different teams.
That said he is definitely a bandwagoner. Now we can sit here and argue what that means in the context of this game but he definitely changes his team whenever something cheaper is discovered. I don't see this as a bad thing but I call it like I see it.
Now as to who played what first.... this is really an irrelevant topic point because it doesn't matter who did what first.. it matters who does it the best. Justin Wong admitted to taking the idea of Wolverine + Akuma from some random online Japanese video. But no one remembers that guy who was using Wolverine + Akuma first, what matters is that Justin is the BEST with this duo in the universe.
Now I will entertain this discussion about who got to Morrigan first or what not. Not going to talk about Vanilla MVC3 because that is even more irrelevant. Beginning of UMVC3 players like Jeo and Omniscythe were one of the few Morrigan players. ChrisG used Morrigan in a troll team until one day he discovered playing Morrigan/Dante/Wright that adding Missiles in there would be super cheap. And thus MorriDoom was born as we know it.
Around that time Omniscythe was also playing various Morrigan teams (some with Wesker). As far as I can tell Omniscythe was the first person to use Morrigan/Vergil/Doom. At this time ChrisG was still juggling with his 3rd, ranging from Akuma, Firebrand, Hawkeye etc. After that Nerdjosh took Omniscythe's team and put Vergil on anchor, then came up with some tricks/combo for that team. After that ChrisG also started using that team and he added his own tricks to the team too.
As proof of this you can watch Curleh Mustache 3 and realize that Omniscythe was in fact using Morrigan/Vergil/Doom when ChrisG was using Morrigan/Doom/Akuma. Around this time Nerdjosh was not using a Morrigan team (he had a bunch of teams like Dante/Frank/Wesker).
TL

R version:
ChrisG, Omniscythe, Jeo and a few others among first to use Morrigan in UMVC3.
ChrisG first to use Morrigan + Doom.
Omniscythe first to use Morrigan/Vergil/Doom.
Nerdjosh first to use Morrigan/Doom/Vergil (put Vergil on anchor which is an alteration from how Omniscythe used it).
Who played what first doesn't matter because it only matters who's the best.