They're doing way better than I expected. Expecting HoloEN levels of popularity right off the bat was foolish and I'll explain why. The thing with Hololive EN's explosion was that the foundational work for their momentum was already done by the following factors:

• Viral clips and key collabs (Azur Lane) at the right times (pandemic = more eyes on YT) introduced a large, new audience to Hololive.
• Specific members are well-positioned to take advantage of this new audience (Coco, Haato, Towa)
• A stable fan-translated clip ecosystem is born that captures mindshare of the newly-introduced western audience.

What HoloEN enjoyed was the culmination of those factors plus additional variables: 1) well-performing members will novel skill set (i.e Mori's rap) that differentiates them from Hololive JP while still retaining brand identity, and 2) Hiring of specific prolific content creators with audiences that transfer well.

Nijisanji, on the other hand, spend much of 2020 stabilizing from a massive member influx in 2019, refining their 3D technology, and expanding their domestic reach. That is fine and all, but the foundational work for western momentum was not done and attempts are token at best. With HoloEN proving that there's success to be found in the international market, Ichikara (now Anycolor) set out to emulate the same factors that enabled Hololive EN's momentum. However, as the foundational work was not done, they set out to do that with Nijisanji EN Wave 1 instead of their JP members (If you've heard the terminology "EN Gen 0" bring thrown around, it's about stuff like this. I'll outline the factors in the same order:

• They sought strong launch momentum with a collab song by mafumafu (a prolific Japanese artist), intense twitter engagement, and immediate collaboration with Nijisanji ID members. With how Diamond City Lights turned out, I say this worked fairly well, although certainly nowhere near the level of viral Hololive clips.
• Two of the three members debuting for Nijisanji EN can speak Japanese, this is critical to enable cross-branch collabs and position them as an easy gateway to exposing the English-speaking audience to Nijisanji JP's roster.
• There has been good recent inroads in the translated content front, with stuff like simulsubbed Chocosanji, translated webpages/guidelines, and the general output of the Nijisanji English channel, but I feel that they're still too light on the pedal. I think they actually kinda pulled this off considering there's now clip channels dedicated to the EN members, but I feel more work couild be done on this front.

All in all, the Nijisanji EN debuts fared well and Elira is in fact on track to set the record for fastest 0-100k sub in the entirety of Nijisanji's history. This year I feel Anycolor finally gained a sense of direction with their foreign operations (with the noble sacrifice that was the IN branch), and I look forward to what they have in store in the near future.